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This paper illustrates a novel design for a MIMO antenna that operates in the frequency range of 26 GHz – 40 GHz (Ka band). The proposed antenna demonstrates 2 x 2 arrangement of electro-magnetically coupled patches that are arranged orthogonally to each other in order to produce a good isolation and ECC with respect to other antennas. The patch of the antenna has been embedded on a Rogers RO 3003 (lossy) substrate. The copper patch has been embedded on the substrate with a thickness of 0.018 mm. The purpose of designing such MIMO Antenna’s is mainly due to their ability to achieve high gain, efficiency and bandwidth and produce low latency rates. The ground of the antenna has been modified various designs with a V slot and a Defected Ground Structure (DGS) which helps in improving the characteristics of the antenna such as gain, VSWR and farfield. The proposed antenna can be easily integrated into modern communication devices due to its highly compact size and it’s easy to fabricate structure which makes it highly versatile to be used for 5G and satellite communication devices. All the parameters of the antenna have been simulated using Computer Simulation Technology (CST).

This paper describes the analysis of Kapton material in antenna design for telecommunication systems. Kapton is usually used in the design of radio and microwave frequency antenna. It is a flexible material and with different dielectric value. The antenna is made of a Kapton substrate, a patch and copper (FR4). The dielectric characteristics of Kapton substrate changes according to temperature. The simulation result shows that the bandwidth of the antenna increased up to 10 MHz with a second layer of Kapton substrate. While the antenna gain decreased 1.19 dB when the dielectric value is increased. Computer Simulation Technology (CST) software was used to analyse the antenna’s performance.

In this paper, the Minkowski fractal patch antenna with combination of rhombic split ring resonator (SRR) structure are proposed for Wireless LAN and WIMAX applications. In the early stage, the normal square patch antenna is mainly designed in CST Microwave Studio simulation software. At that moment, the Minkowski patch antenna was designed using 1st iteration and 2nd iteration technique. The next step is adding the rhombic SRR at side of Minkowski fractal patch antenna. The proposed antenna effect to create a multiband frequency at different location at 2.43 GHz, 2.76 GHz and 5.36 GHz with the reflection coefficient of −16.366 dB, −10.624 dB and −18.030 dB, respectively.

In this paper, a tri-polarized antenna is with X-shaped element for multiple-input multiple-output (MIMO) wireless communication system had been design in CST Microwave Studio and fabricated in the laboratory. This antenna had three different stage of Antenna Design A, Antenna Design B and Antenna Design C. The first stage consists of Antenna Design A1, Design A2 and Design A3 that created to produce single polarization at frequency 2.4 GHz. Then, the Antenna Design B is then made up by joining Antenna Design A1 and Antenna Design A2 in a same antenna structure. The last stage is Antenna Design C that consist three different design - Antenna Design C1, Design C2 and Design C3. These antennas consist three different ports – Port 1, Port 2 and Port 3 that effect tri- polarized antenna. At the Port 3 of Antenna Design C3, the return loss performance of simulation and measurement of the antenna are 2.412 GHz and 2.48 GHz with −23.205 dB and −10.101 dB, respectively.

This work proposed a dual circular-polarized slot antenna for wireless local area network (WLAN) application at 2.4 GHz. The proposed design is simulated by using FR-4 as is substrates. In this work, three stages of antenna had been simulated in CST Microwave Studio. First two antenna, Design 1-A and Design 1-B is containing a single polarized antenna with different feedline port location. An X-shaped structure is located at the middle of the patch at angle of 42.5 degrees. Then, dual feedline port antenna, Design B1 are designed to create dual circular-polarized effect. The return loss S11 results at 2.4 GHz of Design 2-A antenna are - 21.511 dB and–28.48 dB for simulation results and measurement results, respectively. For axial ratio for Port 1 and Port 2 are 0.63 and 1.12, respectively. In the end, the simulation and measured antenna design are compared.

This paper proposed a two layered 2 × 1 Koch Curve patch array antenna design with suspended air gap technique for Wireless Local Area Network (WLAN) application of 2.4 GHz resonant frequency. This proposed patch antenna is using two FR-4 substrate layers with dielectric constant, e r = 4.4 and the electrical conductivity tangent loss, tanΔ = 0.019. It is using the suspended air gap technique between two layers for enhancement effect of antenna gain from 4.89 dB to 5.18 dB. At the upper part of substrate, it consists a two feeding networks that connected the two patch of Koch Curve array patch. Beside antenna gain, this technique also improves the bandwidth and return loss of the antenna. It also contains a Koch Curve array structure at the patch part and have a full ground of copper at the back. This Koch Curve is design based on the basic equilateral triangle with three iteration steps. For the first iteration step, it be made up of the equilateral triangular shaped while the second iteration are added with mirror design of equilateral triangular to create a six segment of star-shaped. For the third iteration step, the equilateral triangle with the length base on previous iteration step is constructed on top of the side line of the base triangle. This third iteration step of the Koch Curve effect the reduction size of the patch antenna from 100 mm × 100mm to only 90mm × 60 mm. The return loss performance at resonant frequency 2.4 GHz is −32.735 dB.

Nowadays, the world has rapidly evolved in the communication system in term of speed and information capacity. Thus, a bow-tie antenna is the suggestion to use because of its exhibits low profile and lightweight. However, the bow-tie patch antenna, inherently have narrow bandwidths and in general are half wavelength structures operating at the fundamental resonant mode. To cater this problem, a slotted bow-tie antenna is designed for wireless applications with consist techniques a pair of polygon-shaped branches structure is implemented on each arm of the bow-tie slot antenna characteristics. The co-planar waveguide is applied to this antenna to effect the wider bandwidth to the antenna. This proposed CPW slotted bow-tie antenna is using FR-4 substrate with dielectric constant, e r = 4.4 and the electrical conductivity tangent loss, tan Δ = 0.019 with substrate dimension of 52.4 mm length × 22.3 mm width. Several parametric studies are done to make sure the suitable dimension for best antenna performance. In this case, several different dimensions of three part are consider to study, such as the microstrip line width (W ml ), height of feedline (H fl ), and the length of branch, L br . The basic antenna without polygon-shaped branches can offer a wider frequency band operation at 2.293 GHz–2.541 GHz with bandwidth of 248 MHz effect by the co-planar waveguide technique. After the addition of the polygon-shaped branches structure to the bow-tie part, its effect a band-notch effect at the 2.46 GHz, while creating a new resonant frequency at two different part at 2.394 GHz and 2.511GHz with resonant frequency of −18.585dB and 19.555dB, respectively.

With the higher speed growth and wide use of wireless telecommunication technology in recent years, the demand for miniature size, low profile, broadband and high gain antennas have increased so rapidly. The slots at the patch antenna is one of the technique can be used to cater this problem. This works proposed a stacked patch antenna with double U-slots structure technique at the patch antenna for Wireless LAN application. This proposed stacked patch antenna is designed on FR-4 substrate with dielectric constant of 4.4 and substrate thickness of 1.6mm with an air gap between the substrate and ground. Firstly, a basic patch antenna had been design. Then, a 65mm × 65mm stacked patch of copper plate was used as the ground plane under-shape patch. By integrating the stacked patch with air gap and the double U-slots techniques, the proposed designed offer an improvement in term of the gain and wide bandwidth of the antenna. A parametric study is of the patch width, patch length and length slot are determined to realize the antenna design. The results show the gain values increased from 7.189 dB to 7.358dB at resonant frequency of 2.4 GHz with a return loss of −14.739 dB. The increment of the length of slot effects the increase value of the return loss of the antenna. Compare with the basic antenna with 100 MHz of bandwidth, the performance for this proposed antenna is 120 MHz with the operating frequency range from 2.34 GHz to 2.46 GHz.

This project proposed a single linear-polarized and a single circular-polarized patch antenna are design for WLAN applications at 2.4 GHz. This antenna is using FR-4 substrate with permittivity, e r = 4.4 and the electrical conductivity tangent loss, tan Δ = 0.019. Three design antennas with same dimension size but with different feed line configuration had been consider as Design A, Design B and Design C. Design A and C have a better measured return loss of − 25.38 dB and − 24.384 dB, respectively. Beside that the Design B shows the performance of − 15.976 dB only.

WiMAX (Worldwide Interoperability for Microwave Access) is a part of wireless communication standards based on the IEEE 802.16 set of standards. In this work, a co-planar waveguide (CPW) patch antenna with octagonal-shaped ring had been design for WiMAX application of 3.5 GHz. This proposed CPW antenna is using FR-4 substrate with dielectric constant, e r = 4.4 and the electrical conductivity tangent loss, tan Δ = 0.019. There are three stages of the antenna design that consist the Design A — basic rectangular patch antenna, the Design B — rectangular patch antenna with octagonal-shaped ring while the last stage is Design C rectangular patch antenna with octagonal-shaped ring with CPW effect. A parametric study of CPW length, LCPW had been done to make sure the best return loss performance and the location of the resonant frequency near to WiMAX frequency range. In this case, nine different dimensions of LCPW that considers is from 11 mm to 19 mm. It shows that the LCPW = 18 mm shows the resonant frequency of T 3.528dB. The CPW patch antenna with octagonal-shaped ring effect a wider bandwidth and create two resonant frequencies. It shows that the proposed antenna covers from the 2.282 GHz to 4.216 GHz, with bandwidth of 1.978 GHz, improve from Design A and Design B of 0.11 GHz and 0.73 GHz, respectively. Two resonant frequencies are located at 2.59 GHz and 3.528 GHz with return loss of −23.89 dB and −34.78 dB, respectively. The antenna gain of Design C is improve to 2.92 dB, after the addition of the CPW technique.

In this paper, two planar inverted-F antennas on a slitted ground plane is proposed for MIMO mobile terminal. This antenna is designed to operate at 5 GHz with 1 GHz bandwidth. In simulation stage, the length and width of slitted are varied. The optimum slit's dimension is shown to be λ/4 length and 0.0333λ width, which produced reflection coefficient of −16.38 dB and isolation of −23.52 dB at 5 GHz, while maintaining 1 GHz bandwidth. It is found that the slitted ground plane has resulted a better isolation of 7.2 dB compared to the full ground plane. Simulated and measured results indicate a satisfactory agreement.

The paper investigates the effect of Minkowski Island split ring resonator (MI-SRR) on the microstrip fractal patch antenna. Firstly, a basic Minkowski Island had been simulated in the CST Microwave Studio. Then, the addition of several sizes of the Minkowski Island split ring resonator on the substrate had been generated tri-band resonant frequencies. The optimal result of this tri-band antenna 2.394 GHz, 3.528 GHz and 5.257 GHz with a gain of 0.874 dB, 1.41 dB and 2.94 dB and the reflection coefficient magnitudes of - 21.945 dB, - 17.154 dB and – 16.536 dB. The reflection coefficient magnitudes of the simulation and fabricated antenna also had been compared. The target application for this antenna is for WLAN and WiMAX.

The need to flnd ways to efiectively utilize the large quantities of agricultural waste that are produced is indicative of the huge potential associated with producing an alternative pyramidal microwave absorber for anechoic chamber-testing applications. We propose the development of a pyramidal microwave absorber that can use sugar cane bagasse (SCB), a byproduct from the production and processing of sugar cane, as the absorbent. In this paper, we report the results of our use of dielectric probe measurement to determine the dielectric constant and loss tangent of SCB. These values were used to model and simulate an SCB pyramidal microwave absorber in Computer Simulation Technology's (CST's) Microwave Studio. This absorber was operated in the microwave frequency range between 0.1GHz and 20.0GHz.

Split ring resonator (SRR) structure can potentially be incorporated onto the truncated pyramidal microwave absorber. This study considers three difierent patterns of edge couple split ring resonator (EC-SRR) designs. Each EC-SRR design is then placed onto the truncated pyramidal microwave absorber. Outer split gap dimension widths of the EC-SRR are varied, and the various S21 performances are compared. This EC-SRR truncated pyramidal microwave absorber is simulated using CST Microwave Studio simulation software. The study and simulation are performed in low frequency range (0.01GHz to 1GHz) as well as in microwave frequencies range (1GHz to 20GHz). Simulation results of this EC- SRR show improvement of re∞ection loss and S11 performance in the high frequency range of the pyramidal truncated microwave absorber.

This work presented the parametric studies work on the microstrip bow-tie patch antenna with split ring resonator structures. Firstly, a basic microstrip bow-tie patch antenna had been simulated using CST Microwave Studio. Then, the split ring resonator structure had been embedded to the patch part of the bow-tie antenna. Several parametric studies on the different dimension had been considered to investigate its return loss performance. These parametric studies done in these works are a different SRR distance from the center part, upper part and bottom part of the bow-tie patch, The return loss of the simulated and measurement of the antenna had been done. It shows that the return loss performance of this the basic bow-tie antenna is −20.16 dB at 2.404 GHz and −19.73 dB at 2.387 GHz for bow-tie antenna with SRR structure.

This project discussed the performance result of the dual band printed folded dipole antenna for wireless communication system. This proposed been simulated using CST Microwave Studio simulation software. The folded dipole structures are implementing at both substrate surface of patch and ground plane. This technique will resonate at 2.4 GHz of frequency for WLAN application. A rhombic shaped are added to the front dipole to disturb the return loss and to introduce a new resonant frequency at 3.5 GHz for WiMAX application. The return loss of the proposed antenna shows return loss of −22.634 dB at 2.4 GHz of frequency with 3.36 dB of gain. At 3.5 GHz, the return loss is −10.380 dB with 4.417 dB of gain.

This paper investigated the effect of two main parameters of patch antenna by using partial ground techniques and addition of modified double W-shaped split ring resonator (MDW-SRR). The results show that these two techniques can be improving the performance of the return loss and bandwidth result of the patch antenna. The proposed antenna covers the frequency range of 1821.1 MHz to 3117.1 MHz with 1309.8 MHz of bandwidth compare to the normal antenna with only 33 MHz (2386 MHz to 2419.4 MHz). Firstly, the basic microstrip patch antenna design (Design A1) had been simulated in CST Microwave Studio simulation software. Secondly, the partial ground effect had been applied at the back of FR-4 substrate (Design A2). Then the Design B1, Design B2, Design B3 of four, eight and twelve units of modified double W-shaped split ring resonator (MDW-SRR) had been added into the patch antenna to compare its return loss, bandwidth, gain and directivity of the patch antenna.

Rubber tire dust-rice husk is an innovation in improving the design of pyramidal microwave absorbers to be used in radio frequency (RF) anechoic chambers. An RF anechoic chamber is a shielded room covered with absorbers to eliminate unwanted re∞ection signals. To design the pyramidal microwave absorber, rice husk will be added to rubber tire dust since the study shows that both have high percentages of carbon. This innovative material combination will be investigated to determine the best re∞ectivity or re∞ection loss performance of pyramidal microwave absorbers. Carbon is the most important element that must be in the absorber in order to help the absorption of unwanted microwave signals. In the commercial

In current telecommunication situation, the antenna with wideband or multi-band effect are important for cater many users' demands. In this research, the works explores the effect of parasitic element on the above of the dual layer microstrip patch antenna. Firstly, a basic microstrip patch antenna with a single layer of substrate (Design A) had been simulated using the CST Microwave Studio software. After that, the addition of another layer of substrate with parasitic element is shown as Design B. This proposed microstrip patch antenna resonates at two different frequencies of 2.396 GHz and at 2.543 GHz of frequency with - 36.8 dB and - 35.644 dB of return loss, respectively. The gain performance for both resonant frequencies at 2.396 GHz and at 2.543 is 5.035 dB and 4.814 dB, respectively. The bandwidth of the Design B antenna is 0.097 GHz (2.354 GHz - 2.451 GHz), had been increase compare with Design A performance of 0.039 GHz (2.380 GHz- 2.419 GHz). The second resonant frequency for Design B is only 0.028 GHz. (2.526 GHz- 2.554 GHz).

A dual-band antenna by use 2 × 2 patch array with L-slot is presented for simultaneously worldwide interoperability for Microwave Access (WiMAX) and wireless local area network (WLAN) application. This 2 × 2 Patch Array with L Slot Antenna is targeted to achieve the gain more than 2 dB for both frequencies by using array technique design. The antenna design structure has been modified by adding a small double L-slot inside inverse double L-slot to obtain the second band resonant frequency at 3.6 GHz for WiMAX respectively. The proposed microstrip patch array antenna comprising of four L shape slot are designed to acceptable reflection coefficient that considered at S11 less than − 10 dB. According to the simulation and measurement result, the 10 dB reflection coefficient bandwidth is about 5.72 % and 7.3 % at both frequencies. The measured gain of the array is 3.65 at 2.4 GHz and 2.0 dB at 3.6 GHz. The agreement between simulation result and the measurement ones is good. The proposed antenna has increased the gain and reduces the reflection coefficient as well as increases the bandwidth of the antenna.

A design of modified H-shaped patch antenna with slots and modified ground plane is presented in this paper. H-patch configuration with modified ground plane is proposed to increase the directivity, bandwidth and reflection coefficient of antenna. The H-shape patch antenna is feed by transmission line. By giving extra slots on top of the patch, it can increase the reflection coefficient of antenna. Measurement results show that the antenna radiates at the frequency of 2.15 GHz with a bandwidth of 0.06 GHz. The resonant frequency of optimized antenna is 2.15 GHz, which has shifted about 30% from the WIMAX application frequency of 2.45 GHz. The minimum reflection coefficient found at frequency of 2.15 GHz is −23.66 dB. The gain of the antenna is achieved at 4.23 dB. The antenna is used to design by using CST Studio Suite 2014 software.

This paper has presents a novel design of compact monopole antenna fed by a coplanar waveguide (CPW) for dual-band applications that targeted to achieve the gain more than 1 dB. The proposed compact monopole antenna has been design only 20 × 35 mm in size. The monopole structure with two inverted U-shaped, L-shaped lateral and coplanar-way (CPW) feed line driven by 50 Ω on one side are designed with reflection coefficient that |s11| less than −10 dB. The U-shaped patch and patch laterally inverted L-shaped have been applied to generate different frequency bands 2.4 GHz and 5.2 GHz by controlling the parameter. According to the simulation and measurement result, the reflection coefficient bandwidth is about 8 – 16.51 % at both frequencies. The measured gain of the monopole is 1.18 dB at 2.4 GHz and 1.45 dB at 5.2 GHz. The proposed antenna has increased the gain and reduces the reflection coefficient as well as increases the bandwidth of the antenna

This work investigate the effect of the defected parasitic element and ring slot on the ground plane at the fork-like shape monopole antenna. Firstly, the basic fork-like shape antenna with a slot and parasitic patch had been designed in the CST Microwave Studio. Then, this antenna had been improved by embedded some defected structure in stage by stage at the ground plane - Design B, Design C, and Design D. The structure had been apply is the parasitic patch and ring slot. The optimal result of this dual-band antenna for Design D is 2.45 GHz and 5.22 GHz with a gain of 4.043 dB and 3.496 dB and the return loss of − 34.875 dB and − 18.03 dB. The target application for this antenna is at 2.45 GHz and 5.2 GHz of the frequency band.

In this paper, a broadband circular polarized antenna with operating frequency at 2.4GHz is proposed. The antennas are designed by using L-probe amendment with inverted patch by using suspended rectangular microstrip antenna (MSA) technique to improve the bandwidth until more than 200MHz. The characteristics of the antenna are analyzed, so that the antenna meets broadband operations at operating frequency of 2.4GHz with return loss less than -10dB. The broadband circular polarized antenna had been designed and simulated by using Computer Simulation Technology (CST) software.

A fractal microstrip antenna with Minkowski Island split ring resonator (MI-SRR) is proposed in this paper. Four minis MI-SRR structure had been connected to the corner of the main Minkowski Island Fractal to improve the bandwidth of the antenna. This antenna radiates at the broadband range from 2.09 GHz to 3.64 GHz with a bandwidth of 1.55 GHz. The first resonant frequencies for this antenna are at 2.292 GHz with - 14.515 dB of return loss while the second resonant frequency is at 3.428 GHz with - 28.585 dB. Design A and Design B have compared its return loss, resonant frequency, gain and bandwidth performance with the previous Minkowski Island antenna. The simulation work in CST Microwave Studio simulation software also had been compared with the measured fractal microstrip antenna.

In this work, a dual layer rectangular microstrip patch antenna with H-slot is proposed for improving the return loss and enhanced gain at 2.4 GHz and 2.45 GHz. The antenna is designed by using CST Microwave Studio is used to design the mathematically based on the rectangular microstrip patch antenna. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the RFID frequency range. It is found that this antenna shows - 18.584 dB at 2.45 GHz and - 19.692 dB at the resonant frequency of 2.442 GHz. At desired along this frequency band, the gain 2.228 dB at 2.442 GHz and 2.756 dB at 2.45 GHz is achieved.

A meandered dipole Yagi-Uda antenna with parabolic reflector for 1.575 GHz of the Global Positioning System (GPS) application is presented. The intention of this work is to attain the consequence for optimum presentations of the antenna established to gain, size and directivity. This antenna radiates at the frequency between 1.52 GHz and 1.88 GHz. The gain for this antenna is 4.521 dB at 1.575 GHz of frequency. This antenna had been shown in the simulation of CST Microwave Studio and compared with the measured antenna results.

In this work, a novel coplanar waveguide (CPW) fed rectangular patch antenna embedded with four L-shaped slots for WiMAX application was proposed. This antenna is designed by using an FR4 epoxy board with dielectric constant, er = 4.4, tangent loss, tan δ = 0.019 and the thickness of substrate, h = 1.6mm. There are two methods applied in this antenna to improve the characteristic of the antenna. The first method is by adding four L-shaped slots on the patch of the antenna to improve the bandwidth of the antenna. In order to improve the bandwidth and gain of the antenna, rectangular stacked patch above the basic patch have been suggested. The simulation of the antenna was done by using Computer Simulation Technology (CST) simulation software. Then, the fabricated antenna had been done to compare with the simulation result. It shows that the addition of a stacked patch on the microstrip patch antenna effect to achieve higher gain performance with 2.687 dB compared with an antenna without stacking patch with only 1.685 dB.

This paper presents an equilateral triangular microstrip antenna with spur lines. The proposed antenna, comprising a triangular planar patch element embedded with two spur line slots. The simulation and fabrication process are performed to understand the characteristics of the proposed antenna. The simulation result is compared with the fabricated antenna. The targeting frequency of this antenna is 0.90 GHz (first resonant frequency) and 1.80 GHz (second resonant frequency). The proposed antenna can improve the bandwidth of GSM 1800 up to 100 MHz. It shows the return loss of - 16.176 dB, bandwidth of 33 MHz (0.919 GHz to 0.952 GHz) and a gain of 3.52 dB first resonant frequency. At second frequency, the return loss are - 28.159 dB with a bandwidth of 115 MHz (1.714 GHz to 1.829 GHz) and gain of 3.380 dB.

This paper proposed the dual band printed omnidirectional antenna for RFID applications at 2.45GHz. This antenna is made up from the double U-stubs and meander collinear structure. The antenna is based on the microstrip type of antenna. The return loss of the proposed antenna at 2.45GHz is -10.61dB and the bandwidth is 122MHz. The gain that has been achieved for this proposed antenna is 3.798dB.

In this paper, a printed two C-shaped monopole antenna array for dual-band WLAN application is presented. The proposed antenna array contains two C-shaped monopole with a shorting line for connecting the two arms of the antenna elements. The purpose of the shorting line is to neutralize the current between the two arms which in return can increase the isolation. A parametric study was also carried out to investigate various parameters that effect the antenna design. The proposed antenna has been designed and simulated by using CST Microwave Studio simulation software. The return loss and gain result of the fabricated antenna is 25.40 dB and 2.91 dB at 2.40 GHz and 16.20 dB and 2.82 dB at 5.20 GHz.

The Minkoski Island patch antenna with complementary split ring resonator at the ground plane are proposed in this work. At the first stage, the normal square patch antennas mainly designed. Then, the Minkowski patch antenna was designed using 1st iteration technique and 2nd iteration technique. The Minkowski fractal shape slot was embedded in the center of the patch to form a Minkowski Island patch antenna. The next step is to apply the partial ground technique and embed the split ring resonator at the ground plane. This antenna was operating in tri-band frequency that is at 2.400 GHz, 3.500 GHz and 5.200 GHz with a return loss of - 11.868 dB, - 13.554 dB and - 18.112 dB respectively. The gain measured of this antenna is 1.286 dB, 1.410 dB and 3.945 dB.

In this work, a modified Minkowski patch antenna had been designed for 2.4 GHz of resonant frequency, f r for wireless local area network (WLAN) application. The proposed complimentary structure of quadruple P-spiral split ring resonator (QPS-SRR) into the patch antenna had been increasing the gain performance. Other parameters that had been considered in this work are return loss, bandwidth, radiation pattern and directivity. This paper also discussed on the effect of single, double and triple sets of quadruple P-shape of the Minkowski patch antenna. This Minkowski patch antenna potentially can be operating the frequency range between 2.362 GHz to 2.427 GHz with a resonant frequency at 2.394 GHz and bandwidth of 65 MHz. The return loss of this Minkowski patch antenna is − 26.072 dB at frequency of 2.4 GHz while the gain is 2.555 dB at frequency of 2.4 GHz.

In this work, rice husk material from paddy had been used as the main material to fabricate the truncated pyramidal microwave absorber. To increase the reflection loss performance, square flower split ring resonator (SF-SRR) had been incorporated onto the rice husk truncated pyramidal microwave absorber. This SF-SRR structure had been located at the top part of the truncated pyramidal microwave absorber. There are five different stage designs to compare the reflection loss performance of the truncated pyramidal microwave absorber. The first design is the normal truncated pyramidal microwave absorber. The next four designs are the truncated pyramidal microwave absorber with different number of SF-SRR structures. This truncated pyramidal microwave absorber with SF-SRR is simulated using the CST Microwave Studio simulation software. This simulation had been performed in between 0.01 GHz to 20.0 GHz of frequency.

Shape is the main parameters that affect the performance of the pyramidal microwave absorber. The pyramidal shape microwave absorber is the most installed absorber in the anechoic chamber. Double pyramid is the hybrid shaped that exist by combining two pieces of normal pyramidal shape. In this paper, four types of double pyramidal shape are used to design pyramidal microwave absorber in simulation software. The difference of these four types of absorber is the distance between two peaks of the double pyramidal microwave absorber. These microwave absorbers are operating effectively in the frequency range from 1 GHz to 20 GHz.

Sugar cane bagasse as is potential agricultural waste to produce an alternative and beneficial product for any suitable application such as pyramidal microwave absorber for anechoic chamber testing application. In this work, the dielectric properties (dielectric constant and tangent loss) of the sugar cane baggase had been measured using the dielectric probe measurement. The sugar can bagasse pyramidal microwave absorber had been modelled and simulate in the CST Microwave Studio using the data from the dielectric probe measurement. This pyramidal microwave absorber had been operating in the microwave frequency range between 0.1 GHz to 20.0 GHz. The targeting reflection loss of this pyramidal microwave absorber is better than − 30 dB. The reflection loss performance comparison with the rice husk also had been done in this work.

This paper had been comparing the performance of the normal patch antenna with single complimentary SRR patch antenna. Four different shapes of single complimentary split ring resonator structure had been incorporated into the microstrip patch antenna - square, circular, triangular, and rhombic. This simulation works had been done in CST Microwave Studio simulation software. The operating frequency of this antenna is 2.40 GHz for Wireless Local Area Network (WLAN) application. The parameters that considered in these works are return loss, resonant frequency, input impedance, gain, radiation pattern and bandwidth. The focusing parameter is to achieve the best gain performance that obtained from the single complimentary split ring resonator patch antenna. The addition of square SRR onto patch antenna will improve the gain from 6.334 dB to 6.508 dB.

Abandoned agricultural waste pose a risk to the environmental and public health. The polyurethane and polystyrene material for designing pyramidal microwave absorber are expensive and not environmental friendly. Tropical crop residue has potential to be used in the electromagnetic testing area. Nowadays, electromagnetic absorbing materials have been increasingly important in ensuring successful Radio Frequency (RF) anechoic chamber testing performance. New material had been research to reduce the cost of designing pyramidal microwave absorber. In this case, dried banana leaves are mixed with polyester and methyl ethyl ketone peroxide (MEKP) to give the best reflection loss performance to the pyramidal microwave absorber compare to the previous research using rice husk. This pyramidal microwave absorber is operating in the frequency range from 0.1 GHz to 20.0 GHz.

Hexagonal base pyramid microwave absorber is the new design of microwave absorber. In this work, two sub-shapes are considered to compare it reflection loss performance. The shapes are hexagonal and truncated hexagonal base pyramid. Three sample of agricultural waste are used that is rice husk, rice straw and banana leaves. Before that, free space measurement technique is applied to define the dielectric constant and tangent loss of the material used. These microwave absorbers have been designed to operate effectively between the frequencies of 1 GHz and 20 GHz.

In designing a microwave absorber for anechoic chamber, there are many condition can affect the performance of microwave absorber. In this work, four conditions are discussed to compare the reflectivity or S11 of the pyramidal microwave absorber. The conditions are different signal source position, areas, angle, and lastly the distance between signal source and pyramidal microwave absorber. These pyramidal microwave absorber are simulated in CST Microwave Studio by using the rice husk as it based material that have dielectric constant, er = 2.9. This absorber has been designed to operate effectively in frequency range of 1 GHz to 20 GHz

Placement variation is one example of parameters that critically affects the performance of RF absorbers. In this work, four designed variation patterns - W, X, Y, and Z were discussed to compare the reflectivity (S 11 ) of designed wedge microwave absorbers. Two sub-shapes were investigated in this work - straight wedge and oblique wedge, each type having three variation of top width dimension. The other investigation includes performance comparison between four and nine elements' array of straight wedges and oblique wedges. These wedge absorbers were simulated using CST Microwave Studio software, with rice husk as its material (dielectric constant, e r = 2.89). The wedge absorbers have been designed to operate effectively between the frequencies of 1 GHz to 20 GHz.

Anechoic chambers signal absorption capability is directly correlated to its performance. One of the main components in enabling signal absorption is the design and material used in designing the absorbers. Two of the main types are pyramidal and wedge-shaped ones. In this work, truncated pyramidal and truncated wedge absorbers for anechoic chamber application have been designed to operate effectively in the microwave frequencies from 1 - 10 GHz. The absorbers were simulated using a fusion of carbon-based material with different features and coating thickness to improve their performance and significant material cost savings. Material consideration for the basic pyramidal and wedge structure has also been taken into account. The designs are simulated using CST Microwave Studio. Simulated results showed that the coating of half the absorber height produced the best performance in terms of signal absorption.

A change in the relative proportions of a mixture of rubber tire dust and rice husks will cause a change in the mixture's electrical permittivity and its ability to absorb electromagnetic energy. An open- ended coaxial probe was used in conjunction with three dielectric mixture equations (the Kraszewski equation, the Landau equation and the Lichtenecker equation) to obtain the dielectric properties of a mixture of rubber tire dust and rice husks (RTDRH) over the frequency range of 7GHz to 13GHz. Lichtenecker's equation for dielectrics proved to be a useful practical formulation for determining the efiective permittivity of homogeneous dielectric mixtures. The efiectiveness of these dielectric mixture equations in determining the efiective permittivity of RTDRH was investigated in this study. A newly developed mixture equation was derived based on these dielectric

Agricultural wastes are considered not useful and are commonly dumped or burned after crop harvesting. Rice husks from paddy (Oryza sativa) are example of agricultural wastes. Rice husks have been investigated as the material for the pyramidal microwave absorbers. The setup for the fabrication and measurement of the rice husks pyramidal microwave absorbers are discussed. An 8£8 array of pyramidal microwave absorber using the rice husks-polyester-MEKP mixture has been designed and fabricated. There are four main stages in this work: the collection of the raw rice husks materials, the mould fabrication, the pyramidal microwave absorber fabrication and the experiments performed to determine the re∞ection loss performance of the rice husks pyramidal microwave absorbers. Experimental