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This paper analyzes and compares three different types of detectors, including CMOS power detectors, bipolar power detectors, and super-regenerative detectors, deployed in the literature for integrated microwave/mm-wave imaging systems in mainstream silicon technologies. Each detector has unique working mechanism and demonstrates different behavior with respects to bias conditions, input signal power, as well as bandwidth responses. Two Figure-of-Merits for both wideband and narrowband imaging have been defined to quantify the detector performance comparison. CMOS and Bipolar detectors are good for passive imaging, while super regenerative detectors are superior for active imaging. The analytical results have been verified by both simulation and measurement results. These analyses intend to provide design insights and guidance for integrated microwave/mm-wave imaging power detectors.

The high operating power density and aggressively scaled geometries associated with 400+ GHz InP-Based DHBTs present a new challenge in device design and thermal management. In order to assess the effects of self-heating on the RF performance, S -parameters of six InP DHBTs with varying emitter dimensions were measured over a 75 °C ambient temperature range. An 8–10% increase in peak f T is observed as the temperature is reduced. Data analysis indicates that reductions in the base and collector transit times and the base–emitter charging times are responsible for the peak f T improvement. The calculated electron velocities exceed 6 × 10 7 cm/s, indicating velocity overshoot plays a critical role in the reduction of the transit times. When emitter scaling are considered, the total transit time variation is directly correlated to the rise in junction temperature. Using previously measured thermal resistance values, a 77–116 °C minimum junction temperature rise is estimated from self-heating. Therefore, the 8–10% increase in peak f T is a reasonable estimate of the performance to be recovered by minimizing self-heating. Improved intra-device thermal management through device design is an important supplement to geometry scaling as a means to enhance device performance.

Traditional compound semiconductor HBT technologies do not allow for the independent design of the intrinsic and extrinsic collector regions commonly found in Si BJT and SiGe HBT technologies. By using a selectively implanted buried sub-collector (SIBS) to optimize the intrinsic collector for reduced transit time and extrinsic collector for reduced capacitance, InP DHBTs technologies can finally have the same flexibility. An improved 200 GHz InP DHBT technology for broadband amplifiers with good forward Gummel characteristics and a DC current gain exceeding 100 is presented. SIBS also allows the fabrication of two types of HBTs, one with a peak fT/fMAX of 208 GHz/225 GHz at IC = 26.2 mA and one with a peak fT/fMAX of 148 GHz/237 GHz at IC = 16.6 mA, on a single wafer, giving the circuit designer additional flexibility. A state of the art traveling wave amplifier with a 61 GHz 3 dB-bandwidth, 29 dB differential gain, and only 2.5 W total power dissipation is presented. At a 45 Gb/s data rate, a 11 V differential output swing is demonstrated while maintaining

Numerous research groups are currently developing high-performance InP HBTs with fT and fMAX greater than 400 GHz. However, the heavily degenerate doping concentrations used in these devices present new challenges to numerical device simulation. This work focuses on three physical phenomena in InP and In0.53Ga0.47As and their implementation in physics based device simulators. First, the use of the parabolic band approximation yields a constant DOS effective mass, but this results in an erroneously deep Fermi-level under heavily degenerate donor concentrations. An empirical model is presented and shown to have good agreement with previously published simulations and experimental data. Second, bandgap narrowing parameters and a table based model are used as a more generic model for compound semiconductors. Third, calculated parameters to address the Mott transition are used to obtain the proper freecarrier concentrations throughout the HBT. The improper calibration or neglect of these three physical phenomena is shown to alter HBT band profiles at thermal equilibrium by as much as 400 meV; the turn-on voltage by approximately 50 mV; and the fT dependence on JC by approximately 18%. � 2006 Elsevier Ltd. All rights reserved.