Matthew A. Morgan

W-band direct detection circuit performance with Sb-heterostructure diodes

W-band direct detection circuits have been designed and fabricated for use in a passive millimeter wave camera. The circuits are based on the recently developed Sb-heterostructure diode. We measure record voltage responsivities in test circuits, up to 8,000 mV/mW from 75 to 93 GHz, with input power from -50 to -30 dBm. Performance was similar in an actual camera frequency processor board with 128 tuned channels. 72% of detectors showed responsivity at or above 6,000 mV/mW and 3% of channels were above 10,000 mV/mW. Since tens of thousands of Sb-heterostructure diodes can be reproducibly and inexpensively fabricated, this demonstrates for the first time the feasibility of large-scale detector arrays utilizing zero bias direct detection circuitry.

164-GHz MMIC HEMT doubler

In this paper, a MMIC frequency doubler based on an InP HEMT and grounded CPW (GCPW) technology is reported. The doubler demonstrated a conversion loss of only 2 dB and output power of 5 dBm at 164 GHz. The 3 dB output power bandwidth is 14 GHz, or 8.5%. This is the best reported result for a MMIC HEMT doubler above 100 GHz.

A W-band low-noise amplifier with 22K noise temperature

A W-band MMIC low-noise amplifier (LNA) was designed and fabricated using NGSTs 35nm InP HEMT process. It was packaged in a WR-12 module and tested at 297K and 17.5K ambient temperatures. At room temperature, the WR-12 LNA module has 26–30 dB gain from 70 to 92 GHz and less than 300K noise temperature from 65–86 GHz. At 17.5K ambient temperature, the WR-12 LNA module has a minimum noise temperature of 22K at 85 GHz and less than 40K noise temperature from 70–96 GHz (below 30K noise temperature from 78–95 GHz). Gain at 17.5K is 27–31 dB from 70 to 94 GHz. Power dissipation cold is 2.1 mW. Analysis is also included to investigate the observed frequency shift with ambient temperature. It is believed that these are the lowest noise temperature measured for a packaged W-band amplifier at both room and cryogenic temperatures.

Full Ka-band High Performance InP MMIC LNA Module

A 0.1-mum InP HEMT Ka-band LNA with high and flat gain, very low noise figure and low VSWR has been developed. Across the entire Ka-band, of 26 GHz to 40 GHz, the MMIC LNA demonstrated associated gain of 21.9 plusmn 0.9 dB and an average noise figure of 1.5 dB with a minimum of 1.3 dB at 34 GHz. The LNA chip was cryogenically cooled to 12 K where it exhibited an associated gain of 23.0 plusmn 1.1 dB and an average noise temperature of 15.5 K, i.e. 0.23-dB noise figure. Two LNA chips were cascaded and assembled into a module. At room temperature, the module achieved an associated gain of 37.6 dB plusmn 1.8 dB and an average noise figure of 1.3 dB. At 15 K, the average noise temperature was improved to 11.4 K with 41.0 plusmn 2.4 dB associated gain

Theoretical and Experimental Study of a New Class of Reflectionless Filter

A design methodology and equations are described for lumped-element filter prototypes having low-pass, high-pass, bandpass, or bandstop characteristics with theoretically perfect input- and output-match at all frequencies. Such filters are a useful building block in a wide variety of systems in which the highly reactive out-of-band termination presented by a conventional filter is undesirable. The filter topology is first derived from basic principles. The relative merits of several implementations and tunings are then compared via simulation. Finally, measured data on low-pass and bandpass filter examples are presented, which illustrate the practical advantages, as well as showing excellent agreement between measurement and theory.

A millimeter-wave perpendicular coax-to-microstrip transition

A novel transition from coaxial cable to microstrip is presented in which the coax connector is perpendicular to the substrate of the printed circuit. Such a right-angle transition has practical advantages over more common end-launch geometries in some situations. The design is compact, easy to fabricate, and provides repeatable performance of better than 14 dB return loss and 0.4 dB insertion loss from DC to 40 GHz.

A W-band GCPW MMIC Diode Tripler

A W-band GCPW (grounded coplanar waveguide) MMIC diode tripler using GaAs PHEMT process is developed. An anti-parallel diode pair is used to produce third harmonic signal and a GCPW band pass filter is used to reject the spurious signal. The measured conversion loss is 18-20 dB from 87 to 102 GHz at 14-dBm input power. It is observed that if the filter were taken out, this tripler could be improved more than 5-dB in conversion loss without significant affecting in rejection performance. In this case, the chip could be reduced at least by half to a miniature size, that is, from 1.5 x 1 mm2 to about 0.8 x 0.8 mm2.

A millimeter-wave diode-MMIC chipset for local oscillator generation in the ALMA telescope

A set of MMIC frequency multipliers and balanced mixers have been designed for the local oscillator system of the Atacama large millimeter array (ALMA). These millimeter-wave elements form a critical link in the active multiplier chains between the relatively low frequency microwave oscillators and the very high frequency submillimeter-wave, cooled multipliers of the LO subsystem. A complete chipset for four frequency bands is described, along with preliminary results on prototypes for two additional bands.

Development of electronically tuned local oscillators for ALMA

We report on the local oscillator (LO) development for the ALMA 64-antenna sub-millimeter wave telescope array. Measurements of output power and AM noise are presented for four wideband electronically-tuned MMIC-based LOs up to 710 GHz.

Medium power amplifiers covering 90-130 GHz for the ALMA telescope local oscillators

This paper describes a set of power amplifier (PA) modules containing InP high electron mobility transistor (HEMT) monolithic millimeter-wave integrated circuit (MMIC) chips. The chips were designed and optimized for local oscillator sources in the 90-130 GHz band for the Atacama large millimeter array telescope. The modules feature 20-45 mW of output power, to date the highest power from solid state HEMT MMIC modules above 110 GHz.