Cellular infrastructure equipment market forces are demanding improvements in power amplifier performance in terms of power, efficiency and linearity for increasingly wider bandwidth signals. This challenge is being addressed with research and advancements on several fronts, including device technology (Si LDMOS, GaAs HBT, GaN), PA circuit architecture (Doherty circuits and high power ICs), and more effective PA linearization techniques.

Nonlinear models can be separated into three categories: physical models, table based models (TBM) and empirical compact models (ECM). Today, the bulk of nonlinear modeling for circuit design applications is accomplished using empirical compact models, but recent developments of more robust table based models could impact that dominance. This workshop will examine the strengths and weaknesses of both TBM and ECM approaches in terms of measurement requirements, computation complexity, model accuracy, required expertise, cost, etc. Some examples of mixed modeling approaches will also be presented.

In this paper we introduce a novel design technique for broadband high dynamic range absorptive voltage con¬trolled attenuators (VCA) on SOI CMOS. The VCA design is based on the classical passive FET ‘Pi’ and ‘Tee’ attenuator structures but uses stacked FET techniques to dramatically improve the signal handling capability. The VCA has 30dB attenuation range over a frequency range from DC to 5GHz and achieves an IIP3 of greater than +47dBm over the entire analog control range.

Only a decade ago, single-chip RF-SoC integration was universally thought to be impossible or at least uneconomical. Nowadays, the pioneering days of single-chip radios are largely over and the innovation efforts are applied to integrating multiple radio cores on the same silicon die. This effort has already resulted in commercial offerings of multi-core wireless connectivity and cellular radios from a few companies, but has revealed some interesting RF co-existence issues: Integrating additional radio cores appears to exponentially increase the overall design and productization complexity, more so than in the case of isolated radios. Why is that and what can be done to address that? What is the ultimate limit of multi-core radio integration?

Recent results from wiSpry and Cavendish Kinetics on RF MEMS switched capacitors on CMOS substrates indicate excellent performance for tunable front ends at 0.5-2.5GHz. These devices can be used in multi-band antennas, matching networks between the antenna and the power amplifiers, and for high-Q designs (Q > 100), in tunable bandpass and notch filters. On the other side, Omron is selling DC-20GHz SPDT switches for relays and instrumentation systems with more than 100 million cycle reliability (compare with 1 to 5 million cycles for standard relays), and Agilent is working on RF MEMS switches up to 67 GHz. There is also a lot of interest from Europe (EPCOS/TDK), and from several Taiwanese, Japanese and Korea companies, mostly for cell phone applications.

A forum and webcast featuring experts in RF nonlinear device measurement and characterization. A panel of experts will discuss solutions and trends in nonlinear device characterization from the perspective of new measurement equipment, techniques and device representation in EDA tools. An open panel discussion session will follow the presentations including audience questions from both live and online participants.

A VHF Doherty amplifier with independent drive-signal control is presented. An I-Q modulator/up-converter is used to produce the driving signals at a carrier frequency of 144 MHz. The amplifiers of the Doherty transmitter are designed using GaN FETs and lumped-element networks. The carrier amplifier operates in class-B with a drain efficiency of 63% while the peaking amplifier operates in class-C with an efficiency of 73%.

A good impedance match between a transmitter and an antenna is essential to achieve power efficiency and maxi¬mize the effective radiated power. In portable scenarios, the antenna impedance is usually subject to wide varia¬tions, mostly due to its interaction with nearby objects. This paper presents a reconfigurable, low loss matching network that provides a wide range of impedance match over a bandwidth that exceeds one octave. Experimental results are provided for the 220 to 450MHz band.

This session highlights two millimeter wave ICs for vector modulation and two mixers in the microwave range. The last paper of the session is an injection locked frequency divider.