Title :
Enhanced linearity and efficiency of HBT power amplifiers for 5-GHz wireless-LANs
Author :
Oka, Tohru ; Hasegawa, Masatomo ; Fujita, Koichiro ; Yamashita, Masaharu ; Hirata, Michitoshi ; Kawamura, Hiroshi ; Sakuno, Keiichi
Author_Institution :
Devices Technol. Res. Labs., Sharp Corp., Nara, Japan
Abstract :
This paper describes two advanced techniques to enhance linearity and efficiency in HBT power amplifiers (PA) for 5-GHz wireless-LANs (W-LANs). The diode-based linearizing circuit successfully compensates the gain expansion of PAs operating at a low quiescent current. The output matching circuit consisting of on-chip MIM capacitors and bond wires effectively reduces the loss of the circuit as well as allowing the miniaturization of the PA module. The PA MMIC fabricated incorporating these techniques achieved an improvement in linear output power and PAE of 2.4 dBm and 4.8%, respectively, compared to our previous PA with the same device dimensions, and exhibited an output power of 22.1 dBm and a PAE of 27.3% at an EVM of 5%, measured with 54Mbps 64-QAM-OFDM signals at 5.25 GHz.
Keywords :
MMIC amplifiers; heterojunction bipolar transistors; millimetre wave power amplifiers; wireless LAN; 27.3 percent; 4.8 percent; 5 GHz; 5 percent; 5.25 GHz; 54 Mbit/s; HBT power amplifiers; PA MMIC; PA module; diode-based linearizing circuit; enhanced linearity; gain expansion; low quiescent current; on-chip MIM capacitors; output matching circuit; wireless-LAN; Bonding; Circuits; Diodes; Heterojunction bipolar transistors; Impedance matching; Linearity; MIM capacitors; Power amplifiers; Power generation; Wireless LAN;
Conference_Titel :
Microwave Symposium Digest, 2005 IEEE MTT-S International
Print_ISBN :
0-7803-8845-3
DOI :
10.1109/MWSYM.2005.1516689