Heterojunction Bipolar Transistor MMIC Research Articles

Design and Optimization of a Highly Linear Power Amplifier with Novel Active Bias Circuit in InGaP/GaAs HBT MMIC Technology

This paper introduces a highly linear power amplifier (PA) that utilizes a 2-μm InGaP/GaAs hetero-junction bipolar transistor (HBT) process. As communication systems evolve in complexity, the demands for the linearity and static power consumption of HBT power amplifiers are becoming more stringent. Typically, there exists a trade-off relationship between linearity and static power consumption in the design process. Hence, this paper proposes a novel active bias circuit for HBT power amplifiers, along with its layout design. The proposed active bias circuit consists of a differential pair and a current mirror structure, designed to enhance PA linearity while maintaining low quiescent current. Additionally, a novel layout structure is implemented to achieve thermal coupling between the RF transistors and the active bias, further improving PA linearity. As a result of the implementation of the proposed active bias and layout structure, the PA demonstrates high linearity in both amplitude modulation to phase modulation (AM/PM) and amplitude modulation to amplitude modulation (AM/AM) performance, while simultaneously maintaining a low quiescent current. The three-stage PA prototype achieves notable performance metrics, including a peak gain of 32.6 dB at 5.6 GHz, gain flatness of ±0.5 dB from 5.15 GHz to 5.85 GHz, and P1dB of 32.1 dBm at a quiescent emitter current of 180 mA.

Design of Power Amplifiers for BDS-3 Terminal Based on InGaP/GaAs HBT MMIC and LGA Technology.

With the development and popularization of the Beidou-3 navigation satellite system (BDS-3), to ensure its unique short message function, it is necessary to integrate a radio frequency (RF) transmitting circuit with high performance in the BDS-3 terminal. As the key device in an RF transmitting circuit, the RF power amplifier (PA) largely determines the comprehensive performance of the circuit with its transmission power, efficiency, linearity, and integration. Therefore, in this paper, an L-band highly integrated PA chip compatible with 3 W and 5 W output power is designed in InGaP/GaAs heterojunction bipolar transistor (HBT) technology combined with temperature-insensitive adaptive bias technology, class-F harmonic suppression technology, analog pre-distortion technology, temperature-insensitive adaptive power detection technology, and land grid array (LGA) packaging technology. Additionally, three auxiliary platforms are proposed, dedicated to the simulation and optimization of the same type of PA designs. The simulation results show that at the supply voltage of 5 V and 3.5 V, the linear gain of the PA chip reaches 39.4 dB and 38.7 dB, respectively; the output power at 1 dB compression point (P1dB) reaches 37.5 dBm and 35.1 dBm, respectively; the saturated output power (Psat) reaches 38.2 dBm and 36.2 dBm, respectively; the power added efficiency (PAE) reaches 51.7% and 48.2%, respectively; and the higher harmonic suppression ratios are less than -62 dBc and -65 dBc, respectively. The size of the PA chip is only 6 × 4 × 1 mm3. The results also show that the PA chip has high gain, high efficiency, and high linearity under both output power conditions, which has obvious advantages over similar PA chip designs and can meet the short message function of the BDS-3 terminal in various application scenarios.

A Receive-Band-Noise Estimation Method and Its Application to a WCDMA Band 11/21 GaAs-BiFET MMIC Power Amplifier Module

This paper proposes a simple but relatively accurate, receive (Rx)-band-noise estimation method for wideband code division multiple access (WCDMA) handset heterojunction bipolar transistor MMIC power amplifier module (PAM) design. The method is based on small-signal and two-tone large-signal simulations, calculating Rx-band noise and helping circuit designers comprehend noise contributions under a large output power operation. Its effectiveness is verified through the simulations and measurements of a WCDMA band 11/21 MMIC PAM featuring an LC trap circuit placed at the base terminal of the first stage. This trap is designed to resonate at the difference frequency between the transmit- and Rx-bands. The PAM accommodating switchable-amplifier chains for triple-power modes—high power mode (HPM), mid-power mode (MPM), and low-power mode (LPM)—is fabricated using our in-house GaAs BiFET process. Measurements conducted under 3.4 V and 1450-MHz-band WCDMA (Third Generation Partnership Project Release 99, 3GPP R99) modulated signals show an Rx-band noise level of less than −136 dBm/Hz and power gain as high as 30 dB at a high output power ( $P_{\mathrm {{out}}}$ ) of 29 dBm. The measured noise level is in good agreement with that of the proposed estimation. The measurements also show that the PAM achieves power-added efficiency (PAE) as high as 41% at the $P_{\mathrm {{out}}}$ of 29 dBm while maintaining the ±5-MHz-offset adjacent channel power ratio (ACLR1) below −40 dBc in the HPM. The PAE values of 22% at $P_{\mathrm {{out}}}$ of 18 dBm and 17% at 7 dBm are obtained in the MPM and LPM, respectively, with the same ACLR1 levels.

Linearised HBT MMIC power amplifier with partially RF coupled active bias circuit for W-CDMA portable terminals applications

A highly linear MMIC power amplifier for wideband code-division multiple-access (W-CDMA) portable terminals has been devised and implemented with a new integrated on-chip lineariser. The proposed lineariser, consisting of an InGaP/GaAs heterojunction bipolar transistor (HBT) active bias circuit partially coupled to RF input power together with a feedback capacitor, effectively improves gain compression with little insertion power loss and no additional die area. The optimised lineariser improves maximum output power (P1 dB) by 2 dB and adjacent channel leakage power ratio (ACLR) by 4 dB, and the implemented HBT MMIC power amplifier exhibits a P1 dB of 30 dBm, a power gain of 30 dB, a power added efficiency of 42% at the maximum output power under an operation voltage of 3.4 V, and an ACLR of -34 dBc at 27 dBm of output power.

A 3.2-V operation single-chip dual-band AlGaAs/GaAs HBT MMIC power amplifier with active feedback circuit technique

This paper describes the design and experimental results for a 3.2-V operation single-chip AlGaAs/GaAs heterojunction bipolar transistor (HBT) monolithic microwave integrated circuit (IMMIC) power amplifier for GSM900 and DCS1800 dual-band applications. The following two new circuit techniques are proposed for implementing the power amplifier. One is an on-chip HBT bias switch which in turn switches the amplifier between 900 and 1800 MHz. The proposed switch configuration allows the switch using a high turn-on voltage of 1.3 V of AlGaAs/GaAs HBT's to operate with a 3-V low supply voltage, because the switch circuitry needs no stacked configuration. The other is an active feedback circuit (AFB) to prevent permanent failure of HBT's in the output power stage even under severe conditions of oversupply voltage and strongly mismatching load. Experimental results revealed that the proposed feedback circuit, which works as a voltage limiter, can protect the output stage HBT's from an excessive collector voltage swing even when the amplifier is operated under a condition of a 5-V oversupply voltage and a 10:1 voltage standing-wave ratio (VSWR) mismatching load. Under a normal condition of 3.2 V and a 50-/spl Omega/ matching load, the IC is capable of delivering an output power of 34.5 dBm and a power-added efficiency (PaE) of 52% in a GSM900 mode, and a 32-dBm output power and a 32% PAE in a DCS1800 mode.

A 50-MHz-55-GHz multidecade InP-based HBT distributed amplifier

The authors report on a 50-MHz-55-GHz multidecade bandwidth InP-based heterojunction bipolar transistor (HBT) MMIC distributed amplifier (DA) which achieves the widest bandwidth and highest frequency of operation so far demonstrated for a bipolar amplifier. The HBT MMIC DA was fabricated using a high-speed 1-/spl mu/m InAlAs-InGaAs-InP HBT base-undercut technology with peak f/sub T/'s and f/sub max/'s of 80 and 200 GHz, respectively, in order to obtain broad-band gain. Key to this work is the successful employment of HBT active load terminations used on both the input and output DA transmission lines in order to extend the low-frequency gain performance down to baseband. With only 82 mW of DC power consumption, the amplifier obtains measured gains of 7.6 dB at 50 MHz, 5.7 dB at 30 GHz, 5.8 dB at 50 GHz, and 3.1 dB at 55 GHz. Simulations of a monolithically integrated InGaAs p-i-n photodetector predicts a baseband 47-GHz photoreceiver response with an effective transimpedance of 38-dB/spl Omega/. The baseband millimeter-wave capability of the InP-based HBT DA and its compatibility with InGaAs photodetectors makes this technology attractive for future generation (>40 Gb/s) high-data-rate light-wave applications.

A low-power HBT MMIC filter based on tunable active inductors

An integrated active microwave filter employing high-Q active inductance simulating circuits is presented in this paper. Heterojunction bipolar transistor (HBT) technology is best-suited for this specific application facilitating the design and giving optimum performance with low power consumption. The prototype triple-resonator filter operates at 2.32 GHz with a 300 MHz -3-dB bandwidth. The power consumption is only 25 mW drawn from a 3-V supply.

High-efficiency HBT MMIC linear power amplifier for L-band personal communications systems

A heterojunction bipolar transistor (HBT) MMIC linear power amplifier is demonstrated for the 1.9 GHz Japanese Personal Handy Phone utilizing the /spl pi//4 DQPSK modulation technique. At an operating voltage of only 3 V, an output power of 21 dBm and a power added efficiency of 35% are obtained along with a modulation vector error of 4.5% and an adjacent channel interference of /spl minus/60 dBc in +//spl minus/600 kHz offset frequency bands.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>