80 GHz MMIC HEMT VCO

In this letter a monolithic voltage-controlled oscillator (VCO) operating in the 77.5-83.5 GHz range is presented. InP HEMTs are used for both the active device and varactor. The VCO demonstrated a tuning range of 6 GHz and an output power better than 12.5 dBm in the entire tuning range     

G-band (140-220 GHz) and W-band (75-110 GHz) InP DHBT medium power amplifiers

We report common-base medium power amplifiers designed for G-band (140-220 GHz) and W-band (75-110 GHz) in InP mesa double HBT technology. The common-base topology is preferred over common-emitter and common-collector topologies due to its superior high-frequency maximum stable gain (MSG). Base feed inductance and collector emitter overlap capacitance, however, reduce the common-base MSG. A single-sided collector contact reduces C_ce and, hence, improves the MSG. A single-stage common-base tuned amplifier exhibited 7-dB small-signal gain at 176 GHz. This amplifier demonstrated 8.7-dBm output power with 5-dB associated power gain at 172 GHz. A two-stage common-base amplifier exhibited 8.1-dBm output power with 6.3-dB associated power gain at 176 GHz and demonstrated 9.1-dBm saturated output power. Another two-stage common-base amplifier exhibited 11.6-dBm output power with an associated power gain of 4.5 dB at 148 GHz. In the W-band, different designs of single-stage common-base power amplifiers demonstrated saturated output power of 15.1 dBm at 84 GHz and 13.7 dBm at 93 GHz     

First On-Wafer Power Characterization of MMIC Amplifiers at Sub-Millimeter Wave Frequencies

We present on-wafer power measurements of 35 nm gate length InP HEMT amplifiers at 330 GHz. Various amplifiers are examined. The maximum output power of 1.78 mW is measured from a three stage amplifier. Additional output power may be possible but limited by our input power source level to saturate amplifiers. This result is the highest frequency on-wafer power measurement we are aware of reported to date, and demonstrates the technique we utilize to be a fast method of evaluating power performance of submillimeter wave amplifiers without the need to package devices.     

Note: Cryogenic microstripline-on-Kapton microwave interconnects

Simple broadband microwave interconnects are needed for increasing the size of focal plane heterodyne radiometer arrays. We have measured loss and crosstalk for arrays of microstrip transmission lines in flex circuit technology at 297 and 77 K, finding good performance to at least 20 GHz. The dielectric constant of Kapton substrates changes very little from 297 to 77 K, and the electrical loss drops. The small cross-sectional area of metal in a printed circuit structure yields overall thermal conductivities similar to stainless steel coaxial cable. Operationally, the main performance tradeoffs are between crosstalk and thermal conductivity. We tested a patterned ground plane to reduce heat flux.     

Power-amplifier modules covering 70-113 GHz using MMICs

A set of W-band power amplifier (PA) modules using monolithic microwave integrated circuits (MMICs) have been developed for the local oscillators of the far-infrared and sub-millimeter telescope (FIRST). The MMIC PA chips include three driver and three PAs, designed using microstrip lines, and another two smaller driver amplifiers using coplanar waveguides, covering the entire W-band. The highest frequency PA, which covers 100-113 GHz, has a peak power of greater than 250 mW (25 dBm) at 105 GHz, which is the best output power performance for a monolithic amplifier above 100 GHz to date. These monolithic PA chips are fabricated using 0.1-μm AlGaAs/InGaAs/GaAs pseudomorphic T-gate power high electron-mobility transistors on a 2-mil GaAs substrate. The module assembly and testing, together with the system applications, is also addressed in this paper     

A>400 GHz fmax transferred-substrate heterojunctionbipolar transistor IC technology

We report transferred-substrate AlInAs/GaInAs bipolar transistors. A device having a 0.6 μm×25 μm emitter and a 0.8 μm×29 μm collector exhibited f_τ=134 GHz and f _max>400 GHz. A device with a 0.6 μm×25 μm emitter and a 1.8 μm×29 μm collector exhibited 400 GHz f_max 164 GHz f_τ. The improvement in f_max over previous transferred-substrate HBT's is due to improved base Ohmic contacts, narrower emitter-base and collector-base junction areas, and slightly reduced transit times. The transferred-substrate fabrication process provides electroplated gold thermal vias for transistor heat-sinking and a microstrip wiring environment on a low dielectric constant polymer substrate     

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 high-gain monolithic D-band InP HEMT amplifier

This paper describes a three-stage monolithic amplifier that exhibits a small-signal gain of 30 dB at 140 GHz. The amplifier employs AlInAs/GaInAs/InP high electron mobility transistor devices with 0.1×150 μm² gate periphery, is implemented with coplanar waveguide circuitry fabricated on an InP substrate, and occupies a total area of 2 mm². Gain exceeding 10 dB was measured on-wafer from 129 to 157 GHz. This is the highest reported gain per stage for a transistor amplifier operating at these frequencies     

Demonstration of 184 and 255-GHz Amplifiers Using InP HBT Technology

In this letter, 184 and 255 GHz single-stage heterojunction bipolar transistor (HBT) amplifiers are reported. Each amplifier uses a single-emitter 0.4 mum 15 mum InP HBT device with maximum frequency of oscillation (f_max) greater than 500 GHz and of 200 GHz. The 183 GHz single-stage amplifier has demonstrated gain of 4.3 plusmn 0.4 dB for all sites on the wafer. The 255 GHz amplifier has measured gain of 3.5d B and demonstrates the highest frequency measured HBT amplifier gain reported to date. Both amplifiers show excellent agreement with original simulation.     

Demonstration of a 311-GHz Fundamental Oscillator Using InP HBT Technology

In this paper, a sub-millimeter-wave HBT oscillator is reported. The oscillator uses a single-emitter 0.3 m15 m InP HBT device with maximum frequency of oscillation greater than 500 GHz. The passive components of the oscillator are realized in a two metal process with benzocyclobutene used as the primary transmission line dielectric. The oscillator is implemented in a common base topology due to its inherent instability. The design includes an on-chip resonator, output matching circuitry, and injection locking port. A free-running frequency of 311.6 GHz has been measured by down-converting the signal. Additionally, injection locking has been successfully demonstrated with up to 17.8 dB of injection-locking gain. This is the first fundamental HBT oscillator operating above 300 GHz.