Teruyuki Shimura

1 W Ku-band AlGaAs/GaAs power HBT's with 72% peak power-added efficiency

High power and high-efficiency multi-finger heterojunction bipolar transistors (HBTs) have been successfully realized at Ku-band by using an optimum emitter ballasting resistor and a plated heat sink (PHS) structure. Output power of 1 W with power-added efficiency (PAE) of 72% at 12 GHz has been achieved from a 10-finger HBT with the total emitter size of 300 /spl mu/m/sup 2/. 72% PAE with the output power density of 5.0 W/mm is the best performance ever reported for solid-state power devices with output powers more than 1 W at Ku-band. >

A GSM/EDGE dual-mode, 900/1800/1900-MHz triple-band HBT MMIC power amplifier module

This paper describes a 3.5-V operation HBT MMIC power amplifier module for use in GSM/EDGE dual-mode, 900/1800/1900-MHz triple band handset applications. With diode switches and a band select switch built on the MMIC, the module delivers a P/sub out/ of 35.5 dBm and a PAE of about 50% for GSM900, a 33.4-dBm P/sub out/ and a 45% PAE for GSM1800/1900. While satisfying an error vector magnitude (EVM) of less than 4% and a receive-band noise power of less than -83 dBm/100 kHz, the module also delivers a 29.5 dBm P/sub out/ and a PAE of over 25% for EDGE900, a 28.5 dBm P/sub out/ and a PAE of over 25% for EDGE1800/1900.

1 W Ku-band AlGaAs/GaAs power HBTs with 72% peak power-added efficiency

High power and high-efficiency multi-finger HBTs (heterojunction bipolar transistors) have been successfully realized at Ku-band by using emitter ballasting resistors and a PHS (plated heat sink) structure. An output power of 1 W with power added efficiency (PAE) of 72% at 12 GHz has been achieved from a ten-finger HBT with the total emitter size of 300 /spl mu/m/sup 2/. 72% PAE with the output power density of 5.0 W/mm is the best performance in the HBTs of which the output powers are more than 1 W at Ku-band.<<ETX>>

A 3.2-V operation single-chip AlGaAs/GaAs HBT MMIC power amplifier for GSM900/1800 dual-band applications

A 3.2-V operation single-chip HBT MMIC power amplifier has been successfully developed for GSM900/1800 applications, featuring on-chip bias circuits switched in turn between 900 MHz and 1800 MHz. The IC delivers a P/sub out/ of over 34.5 dBm and a PAE of over 50% for GSM900, a 32-dBm P/sub out/ and a 42% PAE for GSM1800 (DCS 1800).

A multiband power amplifier using combination of CMOS and GaAs technologies for WCDMA handsets

A multiband power amplifier using combination of CMOS and GaAs technologies (Combo MB PA) which supports quad WCDMA bands (Band V, VIII, II, I) is described. With four chips - two GaAs-HBT chips, a GaAs-HEMT chip, and a CMOS chip - mounted on a 5.5×5mm2 laminate, the Combo MB PA comprises two amplifier chains and two SPDT HEMT band-select switches, covering 824-915MHz and 1850-1980MHz. Each amplifier chain has switchable signal paths corresponding to dual (high and low) power modes (HPM and LPM) for saving battery current in practical handset use. In the PA, driver stages, RF switches, and their bias- and switch-control circuits are integrated on the CMOS chip for cost reduction. Only the final power stages are fabricated in a GaAs HBT process. Measurements were carried out under the condition of a 3.4V supply voltage and a WCDMA (3GPP R99) modulated signal. Due to optimized broadband matching design, the Combo MB PA achieves a power-added efficiency (PAE) as high as 40% at a Pout of 28dBm over 824-915MHz in the HPM while keeping adjacent channel leakage power ratio (ACLR) less than -39dBc. In the LPM, PAE of 15 % at a Pout of 17dBm is obtained with ACLR of less than -40dBc. For 1850-1980MHz, the PA shows 35% PAE with ACLR of less than -37dBc at 28dBm of Pout in the HPM and 14% PAE at 17dBm of Pout in the LPM.

A Current-Mirror-Based GaAs-HBT RF Power Detector for Wireless Applications

This paper describes circuit design and measurement results of a newly developed GaAs-HBT RF power detector for use in wireless applications. The detector features logarithm-like, frequency-independent characteristics. The detector can be also driven with small input power levels, enabling base-terminal monitor which can utilize directivity of a power stage. Since a unique current-mirror-based topology is successfully employed for realizing these features, the detector is easy to implement on a GaAs HBT power amplifier. Measurement results of a prototype detector fabricated with a single-stage amplifier on the same die are as follows. The detector can deliver a detection voltage of 0.4-2.5 V and its slope of less than 0.17 V/dB over a 2-22-dBm output power range at 3.5 GHz while drawing a current of less than 1.8 mA from a 2.85-V supply. The detector is also capable of suppressing voltage dispersion within 50 mV over a 3.1-3.9-GHz wide frequency range operation, and this dispersion is less than one-seventh of that of a conventional collector-terminal-monitor type diode detector.

InGaP/GaAs HBT MMICs for 5-GHz-band wireless applications - a high P1 dB, 23/4-dB step-gain low-noise amplifier and a power amplifier

This paper describes the circuit design and measurement results of two InGaP/GaAs HBT MMICs, a low-noise amplifier (LNA) and a power amplifier (PA), for 5-GHz-band wireless LAN applications. The LNA including all on-chip matching and bias feed circuits delivers a high P1 dB of 13.5 dBm, a 23/4-dB step gain switching, and 2.4/3.6-dB low noise figure while keeping a low current consumption of 9.2 mA at 3 V. The PA featuring on-chip input and output matching exhibits 23.2 dBm of P1 dB and 23.2 dB of power gain with 30% PAE from 3.0-V power supply.

Three-dimensional modeling of thermal flow in multi-finger high power HBTs

Three-dimensional modeling of thermal flow in multi-finger HBTs has been investigated with thermal network method to find out the optimal structure which can effectively reduce the junction temperature uniformly in whole fingers under the high power operation. Thermal cross-talk effects and temperature distribution in a finger or between the fingers are examined. The HBT structure with emitter air-bridge connected to via hole is proposed as an optimal structure. The estimation accuracy of the calculation was confirmed from the good agreement between the calculation result and the measured value of the thermal resistance in HBT with the emitter air-bridge structure.<<ETX>>