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In this paper, flexible, low profile and robust planar monopole antennas are designed and analyzed for its performance over conformal surfaces, intended for Ultra-Wideband (UWB) and Body Centric Wireless Communications (BCWC). By the aid of alike shape (modified rectangular shaped) radiator and truncated ground plane, two compact microstrip fed antennas are designed and fabricated on flexible substrates – Polyamide and Teslin (environmentally friendly, flexible and green-electronics). The proposed polyamide antenna with a size of 50 mm × 40 mm × 0.8 mm, radiates over frequency range from 1.8 to 13.3 GHz and teslin antenna with a dimension of 50 mm × 40 mm × 0.712 mm, covers the frequency range from 1.4 to 13.4 GHz. To validate the designed prototypes, the antennas are fabricated and the impact performance are analyzed, while flexing the antenna from its nominal straight arrangement (bending through its length, width, different bending radius and angles). Further, time domain analysis is carried out in free space and in various bent scenarios with pulse excitation to validate the antennas for UWB applications. The transmission coefficient characteristics (S21) and group delay for various bending conditions are measured and the fidelity factor for all the scenarios are greater than 0.82, which make the antennas good candidate for UWB-BCWC.

This paper presents a bandwidth enhanced, compact planar ultra-wideband antenna design for wireless personal area communication (WPAN) applications. The proposed antenna has fractal based geometry and is constructed using several iterations of a pentagon slot inside a circular metallic structure. The partial ground plane of the basic radiator is tapered, defected and a U slit is etched out from the microstrip feed to improve the −10 dB |S11| bandwidth. The proposed fractal based antenna has an impedance bandwidth from 2.9 GHz to 15 GHz with low profile configuration and is fabricated on FR4 substrate with dimensions of 32 mm × 32 mm × 1.6 mm. To authenticate the designed prototype, the antenna is fabricated and tested for impedance and radiation characteristics. The designed antenna has stable radiation characteristics in the operating band. Furthermore, the antenna is validated for its applicability in WPAN, by calculating fidelity factor through time domain analysis along with the transmission coefficient and group delay measurements.

A compact frequency-agile multiband filtenna is presented in this letter. The proposed reconfigurable filtering antenna performs independent switching between four operating bands viz. 1.8 GHz (GSM), 2.4 GHz (Bluetooth), 3.5 GHz (WiMAX), and 5.2 GHz (WLAN). This switching allows the unused bands to be utilized by the secondary user, making the antenna suitable for cognitive radio applications. An elliptical wideband monopole antenna is excited through a reconfigurable bandpass filter (BPF) integrated onto the 50 Ω transmission line. The BPF comprises four distinct structures to tune to four different frequencies using p-i-n diodes. The proposed filtenna has the reflection coefficient less than −20 dB for all the desired operating bands. Furthermore, this multiband filtenna offers gain of about 1.1, 2.6, 3, and 3.4 dBi at the four frequency bands. The prototype filtenna is fabricated, and the simulation results are verified experimentally.

Millimetre-wave (MmW) frequencies offer large bandwidth with which gigabit data rates can be easily achieved with simple radio architectures. At MmW frequencies, the short wavelength enables integration of the antenna on the same chip as the microwave monolithic integrated circuits. This research work emphasises on the design and development of antipodal linear tapered slot antenna (ALTSA) using substrate integrated waveguide (SIW) technique and its radio link characteristics at 60 GHz for wireless local area network and wireless personal area network applications. SIW feeding technique is used to eliminate the unwanted radiations from feed. The proposed antenna is designed and simulated using three-dimensional (3D) electromagnetic tools. Radio propagation is profoundly site specific and depends on frequency of operation, interference from surroundings and other dynamic factors. To predict signal strength, delay and achievable data rates, it is important to characterise the radio channel. The radio link study is carried out using ALTSA with radio frequency measurement equipment to measure and characterise propagation channels in narrow hallway environment at 60 GHz.

This paper exhibits the design and implementation of a compact dual-band bandpass filter on paper substrate. The proposed filter which works on the principle of signal interference technique has a parallel combination of short-circuited coupled line and an H-shaped network of transmission lines with open stubs. Due to the superposition of signals of the two transmission paths, a second order dual-band bandpass response with four transmission zeroes is achieved. To validate the proposed design, theoretical analysis using the lossless transmission line model is carried out and acknowledged. The developed dual-band filter prototype with center frequencies 1.17 GHz and 4.06 GHz has 3-dB fractional bandwidths of 82.56% (0.69–1.656 GHz) and 20.59% (3.645–4.481 GHz), respectively. The simulated and experimental results are in good congruence with each other. The proposed dual-band bandpass filter can be used in various wireless applications, for example, Global System for Mobile Communications (880–915 MHz), Aircraft surveillance (960–1215 MHz), Indian Regional Navigation Satellite System (1.164–1.188 GHz), Amateur radio (1.24–1.30 GHz), Global Positioning System (1.559–1.61 GHz), Satellite phones (1.616–1.626 GHz), and Satellite communication (3.7–4.2 GHz).