Youn Sub Noh

PCS/W-CDMA dual-band MMIC power amplifier with a newly proposed linearizing bias circuit

A personal communications service/wide-band code division multiple access (PCS/W-CDMA) dual-band monolithic microwave integrated circuit (MMIC) power amplifier with a single-chip MMIC and a single-path output matching network is demonstrated by adopting a newly proposed on-chip linearizer. The linearizer is composed of the base-emitter diode of an active bias transistor and a capacitor to provide an RF short at the base node of the active bias transistor. The linearizer enhances the linearity of the power amplifier effectively for both PCS and W-CDMA bands with no additional DC power consumption, and has negligible insertion power loss with almost no increase in die area. It improves the input 1-dB gain compression point by 18.5 (20) dB and phase distortion by 6.1/spl deg/ (12.42/spl deg/) at an output power of 28 (28) dBm for the PCS (W-CDMA) band while keeping the base bias voltage of the power amplifier as designed. A PCS and W-CDMA dual-band InGaP heterojunction bipolar transistor MMIC power amplifier with single input and output and no switch for band selection is embodied by implementing the linearizer and by designing the amplifier to have broad-band characteristics. The dual-band power amplifier exhibits an output power of 30 (28.5) dBm, power-added efficiency of 39.5 % (36 %), and adjacent channel power ratio of -46 (-50) dBc at the output power of 28 (28) dBm under 3.4-V operation voltage for PCS (W-CDMA) applications.

An InGaP-GaAs HBT MMIC smart power amplifier for W-CDMA mobile handsets

We demonstrate a new linearized monolithic microwave integrated circuit smart power amplifier of extraordinary high power-added efficiency (PAE), especially at the most probable transmission power of wide-band code-division multiple-access handsets. A PAE of 21% at 16 dBm of output power, which is the maximum bound of the most probable transmission power in IS-95 systems, was obtained, as well as 40% at 28 dBm, the required maximum output power, with a single-chip MMIC power amplifier. The power amplifier has been devised with two InGaP-GaAs heterojunction bipolar transistor amplifying chains parallel connected, each chain being optimized for a different P/sub 1dB/ (1-dB compression point) value: one for 16 dBm for the low-power mode, targeting the most probable transmission power, and the other for 28 dBm for the high-power mode. The high-power mode operation shows 40% of PAE and -30 dBc of adjacent channel leakage power ratio (ACLR) at the maximum output power of 28 dBm. The low-power mode operation exhibits -34 dBc of ACLR at 16 dBm with 14 mA of a quiescent current. This amplifier improves power usage efficiency and, consequently, the battery lifetime of the handset by a factor of three.

Cellular/PCS dual-band MMIC power amplifier of a newly devised single-input single-chain network

This paperproposes a novel structure of single-input/chain dual-band power amplifier and reports the InGaP/GaAs hetero-junction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) power amplifier implemented for cellular (850 MHz)/PCS(l750 MHz) dual-band applications. This power amplifer has a single-input port to comply with multiband RF and has a single-chain network to achieve a small chip and module size. In order to reduce quiescent currents for cellular band, the band selecting circuit to control bias current is used to each of drive.andpower stage. The two-stage amplifier has a maximum output power of 30dBm (29dBm) and power-added efficiency (PAE) of 42%(37%) and adiacent channel power ratio(ACPR) of -5ldBc(-48dBc) at the output power of 28dBm(28dBm) under 3.4V operation voltage for cellular (PCS) band.

A common power-stage cellular/PCS/W-CDMA triple-band MMIC power amplifier

This paper describes the design and experimental results of an InGaP/GaAs hetero-junction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) power amplifier for cellular (850 MHz)/PCS(1750 MHz)/W-CDMA (1950 MHz) triple-band mobile terminal applications. This two-stage power amplifier has only one power-stage in common for the triple bands to achieve a small chip and module size for low manufacturing cost. In order to reduce quiescent current for cellular band, the band selecting circuit to control bias current is used to the power-stage amplifier. This power amplifier has the power gain of 30 dB (26 dB, 25 dB) for cellular (PCS, W-CDMA) band and power-added efficiency (PAE) of 43% at the output of 28 dBm for cellular band under 3.4 V operation voltage.

A temperature and supply independent bias circuit and MMIC power amplifier implementation for W-CDMA applications

A novel bias circuit providing a stable quiescent current for temperature and supply voltage variations is proposed and implemented to a W-CDMA MMIC power amplifier. The power amplifier with the proposed bias circuit has the quiescent current variation of only 6% for the -30°C to 90°C temperature change, and 8.5% for the 2.9 V to 3.1V supply voltage change, and the variation of the power gain at the 28 dBm output power is less than ±0.8 (0.05) dB for the ±0.1 V of supply voltage (±60°C of temperature) variation.

Low Power Consumption InGaP/GaAs HBT MMIC Power Amplifier for 5-6 GHz Wireless LAN Terminals

by the Ministry of Science and Technology of Korea and KISTEP (Korea Institute of Science and Technology Evaluation and Planning).