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The presentation will focus on the development of a number of GaN and GaAs MMIC high power and highly integrated solutions covering a range of space, commercial and defense applications. Reported designs will be based on developments from C-Band up to W-band frequencies where focus has been placed on maintaining and maximising parameters such as power added efficiency (PAE), output power, cost and...
This work proposes a behavioral modeling approach suitable for power amplifier (PA) operation under dynamic load modulation. The model accounts for the PA nonlinear dynamic effects by means of 1st order kernel functions of the modified Volterra formulation, extracted from automated Nonlinear Vector Network Analyzer (NVNA) measurements. Validation experiments under wideband load modulation are reported...
In this paper we present a reduced complexity digital predistortion of multiple power amplifiers. The reduction is based on using only one feedback path taking into account the similar characteristics of amplifiers in the MIMO system. After some theoretical basics, the paper presents the results of the experiment trying to give an answer whether the predistortion can be used with limited (in extreme...
In this paper, a GaN HEMT class-E power amplifier (PA) has been designed for efficiently operating under variable load resistance at the 750 MHz frequency band. The desired zero voltage switching (ZVS) of the device can be approximated for a wide range of resistive loads, by means of a simple inductive impedance inverter, derived from [1]. The load-pull contours, obtained from simulations, allowed...
This paper presents a flip-flop-based pseudo-current-mode logic (CML) 2:1 frequency divider designed in 130 nm SiGe BiCMOS technology. We use an auxiliary transistor to increase the current thru the data pair, known as the “keep-alive” bias technique. Thereby one can easily control the asymmetry of the period by tuning the gate voltage of the auxiliary transistor. This enables tunable divider's self-oscillation...
The design and simulation of a Class-E power amplifier with an Inverse Class-B driver are presented. The Inverse Class-B amplifier generates a train of half sinusoids which provides a compromise between using a sine wave and a square wave as the input waveform. The design methodology proposed includes the use of load-pull technique to determine the optimum fundamental-frequency load-impedance of the...
This paper presents a hybrid empirical-behavioral model applied to microwave active devices. The empirical part ensures meaningful, physical response over a wide range of variables, while the behavioral part boosts the accuracy in the particular region of interest. A simple Kriging with zero mean value is employed as the behavioral model. Such hybrid model outperforms the sole empirical model and...
Digital Predistorter (DPD) linearizers are key components for signal integrity and power efficiency in modern communication systems. This article presents a comparative study of the performance of three models for multistandard DPD usage, the Two-Path Memory (TPM) model, the General memory Polynomial (GMP) model, and the Dynamic Deviation Reduction-Based Volterra (DDR) model.
A Ka-band power amplifier (PA) in a differential cascode topology with active biasing is designed, implemented in a 0.25 μm SiGe BiCMOS technology, and characterized. The design presents low power consumption and high Power Added Efficiency (PAE). This PA presents an output power of 12.3 dBm at P1dB with 16.5% Power Added Efficiency (PAE). The PAE peak is 17.5 % and it is centered nearby the P1dB...
This paper presents the design of a frequency selectable oscillator used as part of a new data acquisition architecture for digital predistortion (DPD) of RF power amplifiers (PAs). The proposed architecture aims to alleviate the requirement of high sampling rate analog-to-digital-converters (ADCs) in the data acquisition loop. The oscillator utilizes switchable capacitors with a digital control scheme...
An Indium Phosphide (InP) Double Heterojunction Bipolar Transistor (DHBT) process has been utilized to design two doublers to cover the 94 GHz and 188 GHz bands. The 94 GHz doubler employs 4-finger DHBTs and provides conversion loss of 2 dB. A maximum output power of nearly 3 dBm is measured while the doubler is not entirely saturated. The DC power consumption is 132 mW. The 188 GHz doubler utilizes...
The usage of threshold voltage (Vth) compensation techniques allows to decrease the input quality factor of RF-DC power converters or more specifically RF charge pumps at low levels of input power, and thus enable the implementation of highly sensitive broadband UHF radiofrequency identification (RFID) transponders (tags). In this work, we present a Vth compensation approach using a combination of...
A large-signal modeling approach has been developed for multi-finger devices fabricated in an Indium Phosphide (InP) Double Heterojunction Bipolar Transistor (DHBT) process. The approach utilizes unit-finger device models embedded in a multi-port parasitic network. The unit-finger model is based on an improved UCSD HBT model formulation avoiding an erroneous RciCbci transit-time contribution from...
This paper compares the noise performance of the common-source and the cascode topology. Although the cascode topology has several advantages over the common-source stage, the noise performance degrades due to the channel noise and the induced gate noise of the common-gate stage. To underline the theory two multi-decade GaN feedback power amplifiers were designed in common-source and cascode topology,...
This paper presents an RF CAD assisted approach to accurate characterisation of microstrip nonlinearities in planar microwave circuits fabricated on commercial printed circuit board laminates. The proposed methodology is employed for the analysis of the nonlinear effects in microstrip filters due to weak intrinsic distributed nonlinearity. The results of this study provide useful insights on the optimum...
The internet of things (IoT) and its applications demand for solutions for small and low-power communication devices. Overcoming the drawbacks of UHF radio frequency identification (RFID) a shift of the backscatter communication principle to mm-wave frequencies is desirable. With the significant reduction of the transponder size and wider communication bandwidth, many new applications become possible...
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