Two compact single-chip 94-GHz frequency-modulated continuous-wave (FMCW) radar modules have been developed for high-resolution sensing under adverse conditions and environments. The first module contains a monolithic microwave integrated circuit (MMIC) consisting of a mechanically and electrically tunable voltage-controlled oscillator (VCO) with a buffer amplifier, 10-dB coupler, medium-power and a low-noise amplifier, balanced rat-race high electron-mobility transistor (HEMT) diode mixer, and a driver amplifier to increase the local-oscillator signal level. The overall chip-size of the FMCW radar MMIC is 2 x 3.5 mm2. For use with a single transmit-receive antenna, a 94-GHz microstrip hexaferrite circulator was implemented in the module. The radar sensor achieved a tuning range of 1 GHz, an output signal power of 1.5 mW, and a conversion loss of 2 dB. The second FMCW radar sensor uses an MMIC consisting of a varactor-tuned VCO with injection port, very compact transmit and receive amplifiers, and a single-ended resistive mixer. To enable single-antenna operation, the external circulator was replaced by a combination of a Wilkinson divider and a Lange coupler integrated on the MMIC. The circuit features coplanar technology and cascode HEMTs for compact size and low cost. These techniques result in a particularly small overall chip-size of only 2 x 3 mm2. The packaged 94-GHz FMCW radar module achieved a tuning range of 6 GHz, an output signal power of 1 mW, and a conversion loss of 5 dB. The RF performance of the radar module was successfully verified by real-time monitoring the time flow of a gas-assisted injection molding process

A new integrated W-band frequency source MMIC is presented which consists of a 94-GHz voltage-controlled oscillator (VCO) with large tuning range and a phase comparator, forming a subharmonic injection-locked phase-locked loop (ILPLL). The ILPLL combines conventional injection-locking with an additional phase control loop to improve the locking range of the oscillator significantly. The 4th subharmonic frequency is used as the reference signal. The locking range was increased from 80 MHz without ILPLL to 4.5 GHz with ILPLL by closing the loop with an external dc amplifier. A phase noise of -83 dBc/Hz at 100-KHz offset was achieved. Pseudomorphic GaAs HEMT's and a coplanar circuit topology were used to allow integration into complex single-chip subsystems and flip-chip packaging

A single-chip 94 GHz frequency modulated continuous wave (FMCW) radar module has been developed for high resolution sensoring under adverse conditions and environments. The monolithic microwave integrated circuit (MMIC) includes a varactor tuned VCO with injection port, very compact transmit and receive amplifiers and a single-ended resistive mixer. To enable bidirectional operation of a single transmit-receive antenna a combination of a Wilkinson divider and a Lange coupler was integrated. The circuit features coplanar technology and cascode HEMTs for compact size and low cost. These techniques result in a particularly small over-all chip-size of only 2 x 3 mm2. The packaged 94 GHz FMCW radar sensor achieved a tuning range of 6 GHz, an output power of 1mW and a conversion loss of 5 dB. The RF performance of the radar module was successfully verified by real-time monitoring the time flow of a gas-assisted injection molding process

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A flip-chip mounted W-band amplifier module with more than 15 dB gain between 82 and 105 GHz has been developed, based on a 0.15 µm GaAs PHEMT technology. To predict the influence of the flip-chip transition, an equivalent circuit model of the flip-chip interconnects was developed. Lossy silicon (n-Si) flip-chip carriers were used to successfully minimize parasitic substrate modes and feed back effects. The flip-chip assembled coplanar 94 GHz amplifier MMIC was packaged in a WR-10 waveguide mount, using CPW-to-waveguide transitions realized an quartz substrates