Conferences

A 100GHz Medium Power MMIC Amplifier with 15dBm Output Power using a GaAs Substrate

This paper describes the design and measurement of a PHEMT MMIC medium power amplifier, designed on 2mil thick GaAs substrate for operation at 100GHz. The unconditionally stable design has over 20dB gain and has saturated output powers in excess of 15dBm at 100GHz whilst using a 4V bias supply. The paper will discuss the design methodology and the limits that GaAs MMIC designers are increasingly facing as higher frequency designs become more common and will in particular focus on the trade-off between power and gain as the devices approach their operational limits.

A Paradigm Shift in MMIC Mixers Using Novel Schottky Diode Technology

In this article, we discuss MMIC mixers designed using high performance GaAs Schottky diodes. As opposed to fixed Schottky diode options already on the market, we describe, for the first time, GaAs diodes with forward voltages ranging from 0.25 V to 0.9 V. These diodes enable new circuit capabilities previously not possible in GaAs diode circuits. A state of the art MMIC mixer is developed and exciting new performance characteristics are demonstrated including low LO drive for power sensitive applications and high LO drive for high linearity applications.

Challenges of Wearable Antenna Design

Antenna design for wearable technologies is a challenging task due to the body being in the near-field of the antenna, the highly dynamic nature of the channel and the user acceptance issues. The antenna should be insensitive to the near field effects of the body in order to keep its efficiency high which translates to longer battery life time and to minimize the detuning. Preferably, it could have a reconfigurable gain pattern to satisfy almost contradictory requirements of different links and to cope with the dynamic channel conditions. Finally the antenna should be either small or flexible for the user’s satisfaction while keeping the SAR levels low for safety.  This paper discusses the aforementioned requirements in detail and proposes antennas tackling these challenges.

Integrating 77GHz LNA/Phase Shifter Chip with PCB Microstrip Patch Antenna for Array Applications

For mm-wave radar applications, integrating the antenna element with active components on a single chip, occupies more die area and increases the cost of manufacturing. In an array application, required spacing between the neighboring antennas also causes to employ much larger chip area to handle overall system on a single chip. In this paper, we propose to embed the on-chip LNA/active phase shifter component on the PCB board to combine with the designed microstrip patch antenna and decrease the cost of fabrication. The antenna and passive components are implemented on 130um thick RO3003 board with Er= 3 at 77GHz, while the on-chip LNA/phase shifter is manufactured on 11.4um height silicon dioxide located on silicon substrate manufactured by IHP 0.25 um SiGe BiCMOS process. The circuit is a preliminary prototype to examine the effect of wire bonding and mm-wave on PCB board for applying multiple antenna/phase shifter circuits in a beam-steering array. Simulation and some measurement results of the integrated PCB board will be presented.

Millimetre Wave Automotive Radar

Automotive Radar has been available for around twenty years.  This paper focusses on the evolution of  mm-wave systems operating around 70-80GHz from early Gunn diode systems, through GaAs MMIC based systems, to recent developments in High Frequency Si.  In this time Automotive Radar has gone from exclusivity to a high end option, but will moving to silicon finally make it commonplace?

Practical design approach of RF PA for high efficiency using simulated load-pull and real world network synthesis with control of the harmonics impedances

A practical approach is discussed of how to design relatively broadband RF power amplifier for maximum possible power and efficiency. A non-linear transistor model is used in Microwave Office to extract by Load-Pull simulations the fundamental and harmonics impedances. Then Amplifier Design Wizard is used for the synthesis of real-world matching networks which provide simultaneous control of the impedances at the fundamental and the harmonics frequencies. Microwave Office is used again for accurate final simulations of the synthesised networks and the full amplifier stage.

Software Solutions to Keep Engineers Out of Production

During a typical new product introduction (NPI) the design engineering team provides significant support to the production team.  This supporting role is critical in allowing the business to meet the short-term goals of “getting products out of door” but, crucially, prevents engineers from returning to R&D activities thereby delaying development of “the next big idea”.  To support large-scale production of their family of E-band transceiver modules, Filtronic Broadband have integrated improved Process Flow Management software (FELIX) and new post-test results analysis software (FIDO) into a highly-automated test system (ATE).  These combined software systems perform the production-support role traditionally filled by the engineer who designed and developed the product (offering advice, determining rework required etc.), allowing the engineer to focus on R&D. Additionally, work has focussed on providing easy access to data on key performance indicators. Engineers and managers can rapidly access key production and performance data via an online interface. This work shows how effective use of software systems can lead to reduced costs, higher test site availability, improved throughput and better yield.

X band Direct Digital Synthesis

The ability of the new generation of Digital to Analog Converter (DAC)s to convert from a digital signal directly into high frequency bands can be seen as a large leap in capability allowing greater system flexibility, reduction in component footprint and power consumption. This paper presents a new high speed, high bandwidth Digital to Analog Converter (DAC)  with high sample rate and high output bandwidth which enables the direct conversion of signals to frequencies up to band X. The component features a number of innovative design features which enable the optimization of performance in the different Nyquist zones. These include various output shaping schemes and interface methods. Preliminary results will be presented which show the performance of the circuit at output frequencies greater than 8GHz. The component’s performance can result in highly flexible and waveform agile Radar signal generation systems and also the potential for improving flexibility of future wireless test systems.