Anna Dadello

LNA Design Based on an Extracted Single Gate Finger Model

A GaAs low-noise amplifier (LNA) is designed with first-time success using a technique for HEMT modelling which divides the device into intrinsic gate fingers embedded in an analysable metal structure. The gate finger is characterised by de-embedding metallisation from a standard test structure. The device is then re-built, with any geometry or layout that the foundry allows, and modelled by electromagnetic (EM) analysis. This allows techniques such as asymmetric inductive source feedback in an LNA to be modelled without prior fabrication of custom test structures. The 7-13 GHz, self-biased LNA has state-of-the-art noise figure (NF) of 1.25 dB at mid-band, gain of 20.5 ± 0.1 dB with 10 dB input and output matches, 10 dBm P1dB, 14 dBm Psat and 22 dBm OIP3. Excellent agreement is achieved with simulation. In a 3x3 QFN package the measured NF is 1.36 dB and the gain is 20 dB. The first-time design success achieved here validates the modelling and parameter extraction technique.

A family of 1, 2 and 4-watt power amplifier MMICs for cost effective VSAT ground terminals

A complete family of cost effective power amplifier MMICs for Ka-band VSAT ground terminals has been developed. Taking advantage of a 6-inch, 0.15/spl mu/m pHEMT process on 100-/spl mu/m thick substrate, the amplifiers exhibit high performance at the lower processing cost: the single-ended, 3-stage amplifier MMIC has more than 27-dB gain at 30GHz and 1-watt saturated output power within a chip size of less than 3.9mm/sup 2/. Two versions of 2-watt power amplifiers, differing in bandwidth, have small signal gain of 24 and 21dB between 28 and 32GHz with excellent additional characteristics (36% PAE and 41-dBm OIP/sub 3/); their chip sizes are 9.5 and 7.4mm/sup 2/. Finally, a balanced power amplifier achieves 4watts from 28 to 30GHz, with a power added efficiency of more than 31% and 43-dBm OIP/sub 3/, in a chip area of 14mm/sup 2/. In term of power and gain density per chip area, these results are among the best reported for GaAs pHEMT on 100-/spl mu/m substrates.

Full ETSI E-Band Doubler, Quadrupler and 24 dBm Power Amplifier

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.

A 3-chip MMIC solution for X-Band phased array radar

The performance of a core chip, HPA and LNA that can be used in the front end T/R Modules of an X-Band phased array radar are presented. The core chip is a dual channel device that controls the amplitude and phase states in transmit and receive mode of operation. The 10-Watt HPA is driven directly by the core chip in transmit mode. The LNA sets the system noise figure in receive mode.

Design of broadband, highly integrated, 20-30 GHz and 35-45 GHz MMIC up-converters

The design of broadband, highly integrated up-converters is described. Two up-converters have been designed to reduce the complexity and cost of broadband millimetre wave systems by integrating a number of functions into a compact MMIC. Broadband performance was achieved for 20-30 GHz and 35-45 GHz with OIP3 exceeding 24 and 15 dBm, respectively; 2xLO leakage better than 3 dBm and excellent gain control. To our knowledge, this is the highest level of integration achieved for an up-converter at these frequencies.

A Low Noise Ka-Band Down Converter for Space Applications

A Ka-band down converter has been developed for use in a transponder to be flown on board a Low Earth Orbiting (LEO) satellite called Fedsat. The down converter employs a single Monolithic Microwave Integrated Circuit (MMIC) which combines the functions of a low noise amplifier and a mixer. The down converter unit has been designed with a particular emphasis on the choice of right materials, components, packaging and assembly techniques with a goal to achieve a low cost unit qualified for space environment.

Ka-band transponder for a small LEO satellite

A 30/20 GHz transponder has been developed for a small low-earth orbit (LEO) satellite called FedSat-1. The design of MMICs and efficient horn antennas for the transponder is outlined and measured results are presented. Integration of the components into a compact, lightweight and power efficient communications package is described.

A 35 GHz two-bit amplified phase-shifter

A combined two-bit phase-shifter and two-stage, 27-dBm power amplifier has been designed for Ka-band applications. The integration of these functions allows compact assemblies with low inter-stage losses to be realised while the use of a commercial 6-inch foundry reduces cost. High density applications are made more practicable through the high PAE achieved (40 to 45%), thus easing the heat management problems associated with phased-array applications at high frequencies. The typical mid-band RMS magnitude variation is 1.3 dB with an RMS phase error of 6 degrees, an input return loss of 10 dB and output return loss of 15 dB for all states. The MMIC size is 3.85 mm2.

44-GHz High Power and Driver Microstrip Amplifier MMICs using 6-inch 0.15-μm PHEMTs

A family of robust and cost effective 44-GHz microstrip MMIC power amplifiers has been developed based on a standard 6-inch, 0.15-μm GaAs power pHEMT production process on 100-μm substrate thickness. These amplifiers provide high output powers at 44-GHz with a MTTF exceeding two million hours at 75 °C backplate temperature. The single-ended, 3-stage amplifier MMIC has more than 15 dB small signal gain at 44 GHz and 28 dBm output power for a chip area of 5.6 mm2. For the same frequency band, a balanced 1.25-W power amplifier and a doubly-balanced 2.25-W amplifier achieved linear gain of more than 18 dBm and better than -20 dB S11 and S22, with chip areas of 10.8 and 21.5 mm2 respectively. To our knowledge, in terms of power and power density per chip area, these results are among the highest output power levels reported to date at this frequency for single chip MMICs on 100-mum substrate with acceptable lifetime