Levelling control circuit

Details Levelling control circuit Levelling control circuit

1990-05-08

1991-08-06

Mottola, Steven

Amplifiers

Miscellaneous

Amplifier protection means

330298, 455117, H03G 720

Patent

active

050381121

ABSTRACT:
A levelling control arrangement for an RF transmitter circuit which additionally compensates for filter ripple, i.e. frequency dependant power variations caused by the filter disposed between a transmitter amplifier and an antenna. The forward and reflected power is sampled by a dual directional coupler between the amplifier and the filter. Signals V.sub.fwd and V.sub.rev are thus obtained indicative of the forward and reflected power levels respectively. The reflected signal V.sub.rev is subtracted from the forward signal V.sub.fwd at comparator and the difference signal V.sub.diff is compared with a reference signal Vref at comparator to produce a signal V.sub.c which is used to control the gain of the amplifier in such manner that the power developed by the amplifier increases as the signal V.sub.rev increases and vice versa. To protect against excessive reflected power levels a limiter may be included which causes the power developed by the amplifier to be reduced only if V.sub.rev exceeds a pre-set threshold.

REFERENCES:
patent: 3449680 (1969-06-01), Schilb et al.
patent: 3641451 (1972-02-01), Hollingsworth et al.
patent: 4122400 (1978-10-01), Medendorp et al.
patent: 4547746 (1985-10-01), Erickson et al.
patent: 4859967 (1989-08-01), Swanson

Affiliated with

Also associated with

Rating

Levelling control circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Levelling control circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Levelling control circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1989732