Timo Karttaavi

Technology for millimetre wave radiometers

Technology for millimetre wave radiometers is discussed. Distinction between coherent and incoherent detection is also addressed. As an example, details of the 70 GHz ultra low noise and high stability receivers for the European Space Agency (ESA) Planck Mission is given. These receivers are part of the Low Frequency Instrument (LFI). The LFI receivers will make use of Monolithic Microwave Integrated Circuits (MMIC) and the key components are the Low-Noise Amplifiers (LNA). Indium Phosphide (InP) technology has been used for manufacturing the HEMT and PIN diode MMICs. Recently complete Elegant Breadboard Model (EBB) of LFI 70 GHz receivers have demonstrated a 30 K noise temperature with 16 GHz bandwidth and a 1/f knee frequency of 30 mHz. Described radiometer modules form flexible basis for constructing radiometers with many pixels for millimetre wave imaging and remote sensing applications.

Coplanar 155 GHz MHEMT MMIC low noise amplifiers

This paper describe the small signal properties of four 155 GHz low noise amplifiers (LNAs). The LNAs employs a 100-nm gallium arsenide based metamorphic high electron mobility transistors with gate length of 2times15 mum in coplanar waveguide topology. The scattering parameters and noise figures of the amplifiers are presented. The measured gains at 155 GHz are 14-22 dB with the measured noise figures of 6.7-7.2 dB.

100 GHz push-push oscillator in 90 nm CMOS technology

A 100 GHz fixed-tuned oscillator was designed and fabricated using a 90 nm bulk CMOS process. Push-push mode was chosen to improve the power output. The oscillator exhibits -3 dBm output power at 101 GHz with 27 mW power consumption. The measured SSB phase noise is -85 dBc/Hz at 1 MHz offset Resonators are implemented with transmission lines to avoid the need of high quality capacitors and inductors.

Coplanar 94 GHz Metamorphic HEMT Low Noise Amplifiers

We report four low noise amplifiers for a 94 GHz cloud profiling radar. The LNAs are designed using coplanar waveguides and they were manufactured with a 100-nm metamorphic high electron mobility transistor technology. The chip sizes are 2.00 times 1.00 mm2 and 2.25 times 1.00 mm2. The gate width of the transistor is 4times15 mum. The scattering parameters and the noise figures of the amplifiers were measured at W-band and the results are presented. The measured gain at 94 GHz was 17-23 dB and the measured noise figure 3.0-3.3 dB using a 0.8 V drain-to-source voltage and a drain current of 8-16 mA per stage

A W-band Radar Receiver for Cloud Observations

Cloud observations are of significant importance in the study of long-term climatic trends. These observations require high-resolution radars at 94GHz. We have developed a compact multichip module (MCM) 94GHz radar receiver and the state of the art InP MMICs to construct it. The LNA MMIC determined the noise figure of the receiver, 3dB, and conversion gain of 17dB. This LNA MMIC was complemented by a second harmonic mixer MMIC that had very low conversion loss of 9.5dB despite the operation at second harmonic frequency. The MCM receiver provided the system requirement of 2dB noise figure when cooled to 170K.

Two-way vector modulator SiGe MMIC for millimeter-wave phased array applications

This paper presents a two-way vector modulator integrated circuit aimed for millimeter wave phased array systems. The active vector modulator is based on the Cartesian topology. Phase can be tuned continuously 360 degrees and the usable gain control range is more than 10 dB. The chip includes a low-noise preamplifier and a buffer amplifier in both receive and transmit paths, which are coupled together using a T-junction. The chip can be used from 60 to 80 GHz and the maximum gain is 30 dB at 67 GHz and The chip is processed in 0.35μm silicon germanium technology. Size of the chip including the pads is 2.5 × 1 mm2 from which one vector modulator core occupies 0.3 × 0.3 mm2.

Millimetre wave metamorphic HEMT amplifiers

We present a medium power amplifier covering frequency range from 18 GHz to 40 GHz and two low noise amplifiers for 94 GHz cloud profiling radar. These integrated amplifiers were manufactured using a 0.15 μm GaAs based metamorphic high electron mobility transistor (MHEMT) technology. We measured in on-wafer tests for the medium power amplifier, a small-signal gain of 22.5 ± 2.5 dB at K-and Ka-bands. The measured 1 dB output compression point is better than t13 dBm at K-band and better than +9.5 dBm at Ka-band using a 2.5 volts supply. The scattering parameters and the noise figures of the low noise amplifiers were measured at W-band and the results are presented. The best measured gain at 94 GHz was 16 dB and the noise figure 5.7 dB using a supply voltage of 25 V and current of 60 mA.