Search

A 0.13 SiGe upconverter circuit is presented that is suitable for use in broadband millimetre-wave transmitters and active phased arrays. The circuit accepts four differential IF inputs (I+, I−, Q+, Q−) in the frequency range of DC to 13 GHz. An off-chip X-band LO passes through an on-chip tripler before being used to drive the image rejection mixer. The resultant output may be placed anywhere in the frequency range of 25 to 42 GHz. When all four inputs are utilised the RF signals are combined passively at the mixer outputs to achieve an output referred P1dB compression point of +4.4 dBm without the need for additional amplifiers in the RF signal path. This paper highlights the measured bandwidth and single-tone compression characteristic of the circuit. Layout techniques are also briefly described.

A compact balanced frequency doubler with more than 35 dB odd-harmonic rejection and fractional bandwidth of 73% is presented in this letter. Wide bandwidth and high odd-harmonic suppression is achieved by adopting a new technique for the transformer balun design, resulting in a very low magnitude imbalance of 0.13 dB and a phase imbalance of 0.4° over 7–15 GHz. The balun performance is improved by offsetting the radius of the primary and secondary coils, which reduces the parasitic coupling capacitance. The input and output frequency ranges for the doubler are 7–15 GHz and 14–30 GHz respectively. The circuit was fabricated in 0.13- $\mu \text{m}$ SiGe technology. The chip size is 0.6 mm $\times \, 0.4$ mm.

The results of measurements performed on a GaN high electron-mobility transistor (HEMT) by two different pulse-measurement techniques are presented. By performing two-stage pulse measurements, two distinct current-injection mechanisms responsible for triggering the trapping process are identified. By performing three-stage pulse measurements, the trap center at which the trapping process occurs is identified to be a double-energy-level trap center, which is a trap center with two distinct energy levels between which there is an interaction. This result has a significant impact on the design of more accurate large signal models for GaN HEMTs.

Conventional and additive manufacturing (three-dimensional [3D] printing) techniques for a dual-ridged horn antenna (DRHA) are presented. The different aspects of the conventional manufacturing of a DRHA and the limitations incurred during additive manufacturing are discussed in detail. The antenna design was further optimized for fused deposition modeling and was 3D printed using acrylonitrile butadiene styrene (ABS). The polymer-based print was painted with nickel-based aerosol spray. The coaxial transition is also included in the 3D printed prototype. The antenna was manufactured with the intention of improving the learning and education of electromagnetism and antennas of undergraduate students using a low-cost personal desktop 3D printer. The painted DRHA has a 10 dB return-loss bandwidth of 6621 MHz (1905–8526 MHz) with a peak gain of 11 dBi. The average cross-polarization isolation achieved was more than 25 dB. Rapid prototyping was possible with additive manufacturing, and limitations were addressed with conventional machining processes whenever required. This prototype is the first known ABS-based horn antenna with the coaxial transition embedded into it. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2110–2117, 2016.

An on-chip resonator is designed and fabricated using a standard 0.13- $\mu \text{m}$ SiGe technology for millimeter-wave applications. The designed resonator is based on a unique structure, which consists of two broadside-coupled meander lines with opposite orientation. The equivalent $LC$ circuit of the resonator is given, while the impact of the structure on the resonance frequencies is investigated. Using this structure along with capacitors, a compact bandpass filter (BPF) is also designed and fabricated. The measured results show that the resonator can generate a resonance at 57 GHz with the attenuation better than 13.7 dB, while the BPF has a center frequency at 31 GHz and a insertion loss of 2.4 dB. The chip size of both the resonator and the BPF, excluding the pads, is only 0.024 mm2 ( $0.09 \times 0.27$ mm $^{2})$ .

A higher frequency, over 2 GHz, is suggested for current 4G or 5G wideband applications. By adopting a unique gain control method, an analog-controlled variable-gain amplifier (VGA) with an accurate dB-linear characteristic is presented. The designed VGA not only features large bandwidth, but also has accurate gain adjustment with a relatively wide control voltage range. The VGA has a measured gain range of 24 dB, of which 17.3 dB is dB-linear with less than $\pm$ 0.3-dB gain error. The $-$ 3-dB bandwidth is relatively constant from 2 to 2.2 GHz for the entire dB-linear range. An output 1-dB compression point of 1.8 dBm and a noise figure of 24 dB are measured. Due to the simple structure, the current consumption of the VGA core is only 2.9 mA from a 1.2-V supply, and the size is only ${\hbox{225}}\ \mu{\hbox{m}}\times {\hbox{45}}\ \mu{\hbox{m}}$ , excluding pads. Moreover, the robustness of the designed VGA is verified by means of Monte Carlo simulation.

Characterization of a wide-band transformer balun with low magnitude and phase imbalance is presented in this paper. Excellent balance over a large bandwidth is achieved by adopting two new techniques for the transformer balun design, resulting in a very low magnitude imbalance of 0.12 dB and phase imbalance of less than 1° over 30 to 60 GHz. The tradeoff between the insertion loss and the balance of the balun is investigated. First, the appropriate width of the primary and the secondary coils is selected for a reasonable insertion loss. Secondly, the radii of the primary and secondary coils were offset to reduce the parasitic coupling capacitance, thereby improving the balance of the differential signal. The balun is fabricated in 0.13 μιη SiGe technology. The balun is very compact with chip size of 0.2 mm × 0.145 mm.

High data rate implantable wireless systems come with many challenges, chief among them being low power operation and high linearity. A low noise amplifier (LNA) designed for this application must include high gain, low noise figure (NF) and better linearity at low power consumption within the required frequency band. The down converter also requires a passive mixer to achieve low power and better linearity. In this paper, design is based on an Impulse Response (IR) Ultra-wideband (UWB) receiver operating at (3.1-5) GHz implemented in 0.25 μm CMOS Silicon on Sapphire (SOS). This paper reports the design and measurement of a UWB receiver with a designed and measured linearity of 17 dBm, a gain of 30.5 dB and a minimum NF of 4.5 dB, which make it suitable for implantable radio applications. © 2014 Published by Elsevier Ltd.

Gate junction temperature is presented as the crucial parameter for modeling thermal degradation in GaAs device reliability studies, and sufficient for modeling the impact of temperature on device terminal characteristics. Gate metal resistance thermometry (GMRT) is applied to a GaAs pseudomorphic high-electron mobility transistor to measure its gate junction temperature. It is found that gate leakage current due to impact ionization can interfere with dc GMRT measurements. To the best of our knowledge, for the first time it is demonstrated that this can be largely avoided by instead applying an ac version of GMRT. However, the dynamic resistance of the gate leakage current path can interfere with ac GMRT. Measurements and thermal finite element method simulations of devices at constant power dissipation conclude that the bias dependence of the channel heat source profile affects the gate junction temperature. A parameter extraction technique is presented and used in device lifetime calculations to demonstrate MTTF variations of more than an order of magnitude (despite fixed power) due to bias-dependent self-heating.

The frequency range 25–45 GHz contains point-to-point bands at 28, 32, 38 and 42 GHz, potential implementation of 5G at 28 and 39 GHz and various military applications. Traditionally, short gate length GaAs pHEMT technology has been used to develop products for these frequencies. Alternatively, SiGe HBT technology may offer lower cost solutions for systems that can tolerate lower performance. This paper presents the design and measurements of a broadband SiGe receiver with a noise figure of 6 ± 1 dB over the entire 25 to 45 GHz bandwidth. The measured gain exceeds 20 dB from 26 to 43 GHz and, with gain control, is sufficiently linear to support 1024 QAM in the 35 to 45 GHz range. To the authors' knowledge, this the broadest bandwidth achieved to date with a SiGe receiver at these Ka or low millimetre-wave frequencies.

150 GHz amplifiers fabricated on a commercial GaAs process with an f T of 135 GHz are presented. The core design achieves a gain of 10 dB or more from 105 to 150 GHz and the balanced variant has a bandwidth of 100 to 150 GHz and output power above 8 dBm at 140 GHz. Significantly, this coplanar design was carried out with a model extracted from biased S-parameters up to only 50 GHz taken on a microstrip device with different gate width. The measured S-parameters and output power of the amplifiers agree remarkably well with that predicted by the model.

A 3D printed dual ridged horn antenna (DRHA) is presented. The antenna design is optimized for additive manufacturing and is 3D printed using acrylonitrile butadiene styrene (ABS) and then painted with nickel based aerosol spray. The coaxial transition is also included in the 3D printed prototype. The antenna was manufactured with the intention of improving learning and education of electromagnetism and antennas for undergraduate students using a low cost personal desktop 3D printer. The painted DRHA has a 10 dB return-loss bandwidth of 6621 MHz (1905 MHz–8526 MHz) with a peak gain of 11 dBi. This prototype is the first known ABS based horn antenna with the coaxial transition embedded into it.

© 2016 IEEE. An ultra-compact integrated resonator and bandpass filters (BPF), in silicon-based technology, are presented for millimetre-wave applications. The resonator consists of two broadside-coupled lines in opposite orientations. Using this resonator, a first-order and a second-order BPFs were also designed. To prove the concept, three prototypes of each of the resonator and the first-order BPF were fabricated using a standard 0.13-μm SiGe process. The measured results show that the resonator has an attenuation of 13.7 dB at the resonance frequency of 57 GHz, while the BPF has a centre frequency of 31 GHz and an insertion loss of only 2.4 dB. Excluding the pads, the chip size of both the resonator and the BPF is extremely compact, only 0.024 mm2 that is equivalent to 0.001 λg2. The unloaded Q factor of the filter is higher than other state-of-the-art designs.

The development of transient gate resistance thermometry (T-GRT) is reported. It is a technique used to measure the transient self-heating of a FET's gate metal. Demonstrations of T-GRT are presented at the wafer level on a GaAs pHEMT and an AlGaN/GaN-on-SiC HEMT. Dynamic self heating is monitored from hundreds of nanoseconds to hundreds of milliseconds. Preliminary finite-element simulations across a range of power dissipation levels agree closely with T-GRT at, and beyond, 1 µs after the applied drain pulse. Characterization of dynamic self heating and its application to pulsed applications such as radar are discussed.

This paper reports the investigation of RF GaN HEMTs as integrated power switches in high frequency, high efficiency switching topologies. GaN HEMTs suffer from trap phenomena which degrades the performance of the HEMT when used as power switches. Pulsed IV characterisation revealed upto 50% reduction in the theoretically available output power, at pulse frequency of 500 KHz and quiescent switch voltage of 60V. Transient measurements done a MMIC switching circuit with integrated drivers fabricated in the same process delivered an output power of 5.8 W at a switching frequency of 100 MHz and drain voltage of 30V.

Novel and realistic application of hot-via interconnects to millimeter-wave active and power MMICs is demonstrated for the first time. Power amplifier MMICs in the 80- and 100-GHz range were successfully designed, assembled, and characterized for wire-bond free chip interconnect technology. With hot-via RF transitions, compact E-band power amplifier MMICs directly soldered onto evaluation boards demonstrate 22-dB gain and over 28-dBm output power in the ETSI band of 81–86 GHz, with little performance degradation compared to reference circuits probed with traditional front-side RF pads. Similarly, a broadband amplifier, when interconnected to its matching PCB, delivers 13-dB of gain in the W-band, and 21-dBm P1dB. To the author's knowledge, this work represents the highest frequency demonstration of any soldered millimeter-wave hot-via active circuits onto standard PCBs, with remarkable measured power performance, closely equaling that of ideally front-side RF probed PA MMICs.

A compact planar inverted-F antenna (PIFA) with single layer dielectric load is presented in this paper. The proposed antenna covers 28 GHz millimeter wave frequency bands and can be useful for future 5G hand held devices. The antenna is placed on a mobile phone substrate of dimensions 110 mm × 60 mm reserving 70 mm × 35 mm for a battery, and occupies a small volume of 4 mm × 4 mm × 1.34 mm. The antenna has a wide operating bandwidth (|S11| < −10dB) of 980 MHz (27.47 – 28.45 GHz) and a peak gain of 8.80 dBi with a gain variation of less than 0.55 dB within the antenna bandwidth. The proposed antenna has stable broadside radiation in yz and xz planes with low side lobe levels of −13.3 dB, −14.4 dB, and wide beamwidths of 66.6°, 64.5°, respectively. Radiation efficiency and total efficiency of the antenna vary between 97% – 99% and 88% – 96%, respectively. Antennas impedance bandwidth, gain, radiation, and total efficiency are assessed with and without a battery.

© 2016 IEEE. A compact transformer balun with less than 0.13 dB magnitude imbalance and 0.4° phase imbalance from 7 to 15 GHz is presented. The balun is suitable for use with frequency doublers using a balanced circuit architecture. Measured data for the balun is used to predict the harmonic rejection of the frequency doubler. The fundamental rejection is 29 dB and third harmonic rejection is better than 35 dB. The balun is 420 μm by 320 μm.

A 1.5 V 4.5 mW 3-5 GHz low-noise amplifier (LNA) suitable for power-constraint application is implemented in a 0.25-μm silicon-on-insulator CMOS process.The designed LNA with good input and output impedance matching exhibits gain of 10.3 dB and 2-2.9 dB noise figure within the 3-5 GHz band. Moreover, the -3 dB bandwidth of the presented LNA is insensitive to process corner variations. A third-order input intercept point of -5 dBm is also achieved for the LNA at 3.6 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:89-93, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27262 Copyright © 2012 Wiley Periodicals, Inc.

The integrated design flow that links simulation, layout, and electromagnetic (EM) analysis is the foundation for modern RF/microwave integrated circuit (IC) design. The inclusion of thermal simulation in this flow is now possible with modern thermal solvers linked into RF/microwave integrated design tools. Silicon germanium (SiGe) heterojunction bipolar transistor (HBT) power amplifier (PA) design is used as an example where such a flow is most beneficial due to numerous issues such as array sizing and thermal runaway. An electrothermal flow is discussed relative to some overall metrics for design flows and that incorporates the availability of an integrated thermal solver into the earliest parts of, and potentially throughout, the entire design flow. The result is a flow that potentially reduces iterations during the design process and boosts design performance by freeing up margin.

This paper presents a low power, low drop-out (LDO) voltage regulator, designed and implemented using 0.18 micron CMOS process. With a supply voltage of 1.8V, 50mA current and with a single compensation capacitor of 1pF. A constant transconductance current reference is used as a bias circuit for the Error Amplifier. The maximum output load current is 50mA at a regulated output voltage of 1.68V.The voltage regulator delivers a full load transient response of 5.5mV overshoot and 3.4mV undershoot. Furthermore, the LDO PSRR rating is −73dB @ 16.7MHz, and a relatively low power of 90mW.

A digitally controlled half-width microstrip leaky-wave antenna (LWA) is presented for fixed-frequency beam scanning. The free edge of a half-width microstrip line is loaded with a number of periodic interdigital capacitors. Each capacitor is connected to the ground plane by a digital switch. By dynamically changing the reactance profile at the free edge of the microstrip the beam direction is changed at a fixed frequency. Full-wave numerical simulations show that the antenna has the ability to scan the main beam from 35° to 56 ° at 5.75 GHz. Refereed/Peer-reviewed

This paper reports on the development of high frequency, high efficiency integrated supply modulators for airborne and space based high power amplifier modules. The power switches within the integrated modulators were RF HEMTs optimized for power amplifier applications. The modulators were fabricated in commercial foundry GaN process and delivered 10W of output power with an efficiency of 83.5% while switching at a frequency of 100 MHz. Development of high frequency supply modulators paves the way for integration of the HPA and modulators onto the MMIC die and on-chip drain bias modulation for efficiency enhancement of the HPA.

A transformer-coupled frequency quadrupler with 50% bandwidth is designed in a 0.25μm SiGe process. The quadrupler covers an output frequency range from 36GHz to 60 GHz with a total power consumption of 38.5mW for a supply voltage of 2.5V. To fulfil the requirement of harmonic suppression, a novel on-chip asymmetrical Marchand balun structure is adopted to compensate the phase and amplitude errors across a wide bandwidth, so that the 3rd- and 5th harmonic suppressions of more than 30-dB can be achieved. The transformer-coupled approach along with a common-base configuration is adopted to enlarge the bandwidth of the multiplier.

© 2015 ICST. This paper reviews the state-of-art of the subthreshold level design energy harvesters for powering biomedical implants. Power consumption and lifespan are crucial requirements for the electronic circuitry of implantable systems. In order to meet these challenging requirements, a design for an energy harvester that operates in a subthreshold level offers a promising solution.

One of the important components of a receiver is the low noise amplifier (LNA). The challenges of LNA design include ability to achieve high gain, low noise figure, and better linearity at low power consumption within the required frequency. In this article, our design is based on Impulse Response (IR) Ultra Wide-Band (UWB) transceiver operating at 3.1–4.6 GHz. Hence, the LNA designed has been optimized for low noise figure, considerably high gain and better linearity at low power consumption, which make it suitable for implantable radio application. The process technology used here is 0.25 μm CMOS Silanna process. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1399–1401, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27588

Electromagnetic Bandgap (EBG) structures exhibit large continuous operational regions as a function of frequency over which they will not allow a signal to propagate. A subclass of bandstop filters, EBG structures stop a signal from passing through by having signals not propagate (vs. some other means of signal rejection, like reflection) in abeyance of Maxwell's Equations. Typically, EBG performance is achieved by modulating the geometric properties of an electromagnetic-guided or radiating structure so as to create a periodicity which induces the EBG and as such is not tuneable [1] if implemented as integrated circuits (IC) or printed circuit boards (PCB).

For transceiver design in low cost CMOS technologies, one of the most challenging elements is the voltage controlled oscillator (VCO), especially if designed for low power. A VCO has been designed and measured where a MOS transistor is used as a varactor, as part of strategy to obtain the wide tuning range of 500MHz. Phase noise was measured and found to be -111dBc/Hz at 1MHz offset at an oscillation frequency of 3.2GHz. The VCO, implemented in 0.25μm Silicon on Sapphire (SOS) CMOS, consumes 600μW of DC power from a 1.2V source and is suitable for implantable UWB applications. © 2013 IEEE.

A pulsed I-V thermal resistance Rth measurement method is formulated and applied on-wafer to a GaAs MMIC pHEMT. An investigation of device dispersion phenomena assesses their impact on the measurement. It is found that performing the Rth measurement using two quiescent bias points in close proximity (situated beyond the knee voltage yet prior to drain voltages that result in significant levels of gate leakage due to impact ionization) improves the accuracy of the method. Extraction of thermal coefficients characterizes the drain current reduction due to heating, allowing for an efficient calculation of Rth with improved precision.

Commercial RF MMIC fabrication process technologies were investigated for fabrication of integrated switching power converters. Pulsed IV characterization of GaN FETs revealed ON resistance dependence on off state bias, and current collapse at high temperatures. The degradation in ON resistance and current collapse can severely impact the efficiency of switching circuits fabricated in these processes.

This paper outlines the popular circuit tuning strategies reported for the implementation of reconfigurable low-noise amplifiers (LNAs). It presents a continuously-tuned LNA intended for multi-standard applications as well as enhancing the yield of conventional narrowband LNAs. The presented LNA is designed and implemented in a 0.25μm silicon-on-sapphire (SOS) CMOS process. It uses MOS-varactors at the output to continuously tune its load resonance frequency and input matching frequency without the need of a tunable input network, achieving optimized power consumption and noise figure (NF). The post-layout simulations show that the designed LNA can be continuously tuned from 2.6 GHz to 3.5 GHz. Over this frequency range, an input IP3 of of -12 dB, gain of 17 dB and a NF of less than 2 dB have been achieved with 3.4 mW of power consumption at 1.8V. © 2013 IEEE.

A half-width microstrip leaky-wave antenna (HW-MLWA) is designed with forward (broadside-endfire) and backward (broadside-backfire) scanning capability. One feed and 50 ω load are connected at each end of the radiating element with a simple feed network and controlled switches that allow the antenna to scan in both forward and backward directions. The main beam is steered at any operating frequency by changing the admittance between the free edge of the radiating element and the ground. This is done by connecting 30 lumped capacitors (1 pF each) to the free edge of the radiating element with a total of 30 switches and vias. The antenna can scan a range of 34° in both forward and backward directions. © 2013 IEEE. Refereed/Peer-reviewed

Changing the electromagnetic bandgaps (EBGs) and hence the stopbands in a multistate periodic microwave circuit is investigated experimentally. The state of the prototype circuit, consisting of 24 unit cells, is changed by closing or opening gaps in selected unit cells. This varies the periodic loading along the circuit and hence the EBG. In most states, the circuit behaves as a bandstop filter, and its stopband width and location are determined by the circuit state. Experimental results confirm that the first stopband width can be as large as 63% (at 4.92 GHz) or can be absent. The EBG leads to excellent isolation around 40 dB in the stopbands. Sharp roll-off between passbands and stopbands (upto 120 dB/octave) and small length compared to microstrip filters with similar cut-off and roll-off characteristics are other advantages of the proposed platform

An implantable high gain/power quotient variable-gain wideband low-noise amplifier (LNA) suitable for capsule endoscopy application is implemented in a 0.25 μm silicon-on-insulator CMOS process. With a current-reused topology and wideband matching network, the presented LNA exhibits peak gain of 13.8 dB, 2.3 dB noise figure, more than 1 GHz bandwidth and 5 dB gain tuning range with good input and output impedance matching. The LNA consumes only 1.8 mW DC power from a supply voltage of 1.5 V. An excellent average gain/power quotient of 6.8 dB/mW is achieved. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2563–2565, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27111

A 4 th-order Butterworth OTA-C lowpass filter based on voltage mode multiple loop feedback (MLF) inverse follow the leader feedback (IFLF) structure is implemented to support both MB-OFDM UWB and low data rate IR-UWB applications. The filter is implemented using a fully-differential linear operational transconductance amplifier (OTA) in 0.25μm SOI CMOS process. A positive feedback topology is used to form a negative resistance load; in such a way, the DC gain of OTA is enhanced. Moreover, the linearity is improved by means of active biasing. AWR simulations in a 0.25μm SOI CMOS process with 2.5V power supply have shown that the cut-off frequency of the filter ranges from 120MHz to 280MHz and dynamic range is about 54dB. The total power consumption is only 32mW at 250MHz cut-off frequency. © 2012 IEEE.

Implant-able wireless body area networks (WBAN) are a promising technology for health monitoring and treatment for patients requiring special care and monitoring, where sensors are placed inside the human body to carry out measurements which may include telemetry or video streaming. Ultra Wide- Band technology (UWB) is investigated as a candidate for the proposed implanted wireless body area sensor network due to its wide frequency spectrum and, hence, its low bit energy. UWB is introduced and then explored in terms of system constraints and circuit implementation. The main focus of the paper is to describe how applicable UWB is used for implant WBANs and to invite future work on designing a radio capable of being installed inside the human body for medical care and monitoring. We have presented the RF front end receiver in 0.25µm CMOS Silanna process.

A GaAs pHEMT frequency doubler, a quadrupler and a power amplifier for E-band applications have been demonstrated to achieve useful output power and power added efficiency (PAE) over a wide bandwidth. The doubler and quadrupler circuits include medium power amplifiers to increase their gain and output power. The doubler has a measured output power greater than 15 dBm over the entire 15 GHz bandwidth of the European Telecommunications Standards Institute (ETSI) E-band specification. The quadrupler has similar output power over the ETSI E bands with a maximum output power of 19.2 dBm. The power amplifier has a maximum measured output power of 24.2 dBm (265 mW) and exceeds 23 dBm (200 mW) over the ETSI E bands. This amplifier has a measured small signal gain of 15 dB and the input and output return losses exceed 15 dB. Its measured PAE is above 8% across the ETSI E bands. This is the highest saturated output power (Psat) and PAE for a power amplifier spanning the full 71 to 86 GHz span of the ETSI E bands for any semiconductor system. Good agreement is demonstrated between measurement and simulation.

This paper presents improvement technique on linearity of a CMOS double balance Gilbert cell mixer with considerable high conversion gain at low power consumption. The mixer consists of inductive source degeneration in the transconductance stage providing impedance matching to improve linearity of the mixer. The mixer was designed to operate a Radio Frequency (RF) signal of 4GHz, a Local Oscillator frequency (LO) of 3.75GHz, thus providing an Intermediate Frequency (IF) of 0.25GHz. The circuit presents an Input third order Intercept point (IIP3) of +1dBm. A conversion gain of 10.45dB and a single sideband noise of 8dB over the band width. The DC power consumed by the core mixer is 4.5mW. The proposed active mixer design was made in 0.25µm CMOS Silanna process, suitable for wideband applications.

This paper presents a diode varactor and MOS varactor voltage control oscillators using 0.25μm CMOS technology, proposed for Ultra Wideband application. The VCOs are designed for 3-5GHz UWB Impulse Radio, The VCO's has 107.6 dBc/Hz and 108.8 dBc/Hz phase noise at 1 MHz offset frequency. The diode varactor VCO has a tuning range of 300 MHz and the MOS varactor VCO has a wider tuning range of 610 MHz which is very difficult to achieve. Their power consumption at the maximum oscillation frequency is 2.26 mW from a 1.2 V voltage source, with 9 dBm output power which is very low compared to the conventional VCO in similar process design. © 2012 IEEE.

A recently proposed tunable microwave periodic structure requires many switches to dynamically change its microwave propagation and radiation characteristics. The performance of a discrete Field Effect Transistor (FET) switch package, suitable for the structure, is investigated in two potential configurations. In one configuration, the switch is co-planar with the ground plane and in the other it is on a different surface. Measurements made on two test boards confirm that when the switches are turned “on” the switch insertion losses are not significantly different between the two configurations. However when the switches are turned “off”, locating the switches on the ground plane provide better isolation between RF ports.

The aim of this work is to develop a scalable small signal HEMT model. We propose a general intrinsic model “unit cell” to build larger transistor devices according to our need and model the metal according to individual geometry using a lumped element network. The challenge we address is extraction of this network from measurement. The parameters of the intrinsic part of the transistor have been extracted from different size of transistors and scaling rule applied to the unit cell. We used MathCAD worksheet to de-embed the TriQuint transistor parameters. Multiple cells are used to build larger devices and we showed that coupling between cells with lumped element affects the S-parameter responses. The interconnection with lumped elements was varied according to the need to fit with larger device responses.