Amplifiers – With semiconductor amplifying device – Including gain control means
Patent
1998-06-30
1999-12-07
Pascal, Robert
Amplifiers
With semiconductor amplifying device
Including gain control means
330279, H03G 310
Patent
active
059990562
ABSTRACT:
A circuit includes a transconductance device which converts an input signal voltage to a signal current. An output terminal is coupled to receive signal current from the transconductance device. A gain-control circuit has an impedance network coupled to the output terminal to maintain a constant impedance at the output terminal and selectively steers current from the transconductance device through at least first and second different nodes of the impedance network to vary the current supplied to the output terminal. The circuit has reduced noise figure degradation as compared to known current steering circuits by controlling gain without dumping signal current directly to the supply and without changing the impedance at the output terminal. The circuit is particularly useful in the RF section of radio receivers and transmitters, such as in cellular phones.
REFERENCES:
patent: 4380739 (1983-04-01), Velo
patent: 4462003 (1984-07-01), Takamatsu
patent: 4839611 (1989-06-01), Kukulinsky
patent: 5233309 (1993-08-01), Spitalny et al.
C.D. Hull, A Direct-Conversion Receiver for 900 MHZ (ISM Band) Spread-Spectrum Digital Cordless Telephone, 31 IEEE Journal of Solid-State Circuits, No. 12, pp. 1955-1963 (Dec. 1996).
Choe Henry
Pascal Robert
Philips Electronics North Amercia Corporation
Wieghaus Brian J.
LandOfFree
Variable gain amplifier using impedance network does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Variable gain amplifier using impedance network, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable gain amplifier using impedance network will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-828664