Title :
A 1.4-dB-NF variable-gain LNA with continuous control for 2-GHz-band mobile phones using InGaP emitter HBTs
Author :
Aoki, Y. ; Fujii, M. ; Ohkubo, S. ; Yoshida, S. ; Niwa, T. ; Miyoshi, Y. ; Dodo, H. ; Goto, N. ; Hida, H.
Author_Institution :
Syst. Devices & Fundamental Res., NEC Corp., Ibaraki, Japan
Abstract :
We designed a continuously variable-gain low-noise-amplifier (VG-LNA) circuit with a noise figure (NF) of 1.4 dB. This VG-LNA has a diode-loaded emitter follower and a variable-current source. The diode-loaded emitter follower enables gain control without NF degradation at the maximum gain; the variable-current source improves the linearity and widens the range of gain control. It was fabricated by using InGaP-emitter hetero bipolar transistors (HBTs) and has an NF of 1.4 dB at maximum gain, 1.95 GHz, and a 3-V supply voltage. Its maximum gain is 15 dB, its input 3rd-order-intercept-point (IIP3) at the maximum gain is 3.4 dBm, and the gain-control range is 40 dB. The obtained of NF of 1.4 dB is the lowest so far reported for a continuously controlled VG-LNA.
Keywords :
III-V semiconductors; UHF amplifiers; UHF integrated circuits; bipolar analogue integrated circuits; gain control; gallium compounds; heterojunction bipolar transistors; indium compounds; integrated circuit noise; mobile radio; telephone sets; 1.4 dB; 15 dB; 2 GHz; 3 V; InGaP; InGaP emitter heterojunction bipolar transistor; continuous control; diode loaded emitter follower; gain control circuit; linearity; maximum gain; mobile phone; noise figure; third-order intercept point; variable current source; variable-gain low-noise amplifier; Circuits; Degradation; Diodes; Dynamic range; Gain control; Heterojunction bipolar transistors; Mobile handsets; Noise figure; Noise measurement; Voltage;
Conference_Titel :
Radio Frequency Integrated Circuits (RFIC) Symposium, 2001. Digest of Papers. 2001 IEEE
Conference_Location :
Phoenix, AZ, USA
Print_ISBN :
0-7803-6601-8
DOI :
10.1109/RFIC.2001.935682
