US 4,422,047 A · Solid state autotune power amplifier

Abstract

A solid state, band-pass filtered, RF power amplifier for equalizing the response of an amplified RF signal across the entire tuning range of a multi channel transmitter is disclosed. An RF signal is applied to the input of a low noise FET amplifier with a portion of the signal coupled off into a frequency counter which in conjunction with a digital switching logic selects a path through a band-pass filter having characteristics that reduce the broadband noise of the RF signal passed therethrough. Additionally, a dual directional coupler samples the output of the power amplifier with the forward sampled signal being used to control the amplifier output to a preselected level and the reverse sampled signal being used to reduce the amplifier output signal in proportion to an increase in the voltage standing wave ratio load between the amplifier and the transmit/receive switch.

Claims10

Dependent claims

A method of automatically tuning an R.F. power amplifier to the R.F. signal generated in a multichannel radio transmitter and applied to the input of the R.F. power amplifier so as to provide equal response across all transmission channels of the radio transmitter, comprising the steps of:

(a) determining the frequency of the R.F. signal;
(b) automatically selecting one of a plurality of band pass filters (BPF) having separate band-pass characteristics which collectively cover the bandwidth of all channels of the radio transmitter, basing said selection on said frequency determination;
(c) passing the RF signal through said selected BPF for reducing broadband noise;
(d) amplifing said filtered RF signal to a preselected level;
(e) sampling said amplified and filtered RF signal;
and
(f) controlling the magnitude of said amplified and filtered RF signal with said sample and in functional relation to said preselected level and a Voltage Standing Wave Ratio (VSWR) load of the RF power amplifier.

4 more elements

An automatically tuned, solid-state R.F. power amplifier responsive to an R.F. signal generated in a multichannel radio transmitter to automatically tune the amplifier to provide equal response across all channels of the radio transmitter, comprising:

(a) means for determining the frequency of an RF signal inputted into the RF power amplifier;
(b) means responsive to said frequency determining means for automatically selecting one of a plurality of bandpass filters (BPF's) having separate band-pass characteristics which collectively cover the bandwidth of all channels of the radio transmitter and thereafter coupling the RF signal through said selected one BPF for filtering and reducing broadband noise;
(c) an amplifier connected to said selected one BPF and operative to receive and amplify said filtered RF signal to a preselected level and outputting said amplified RF signal;
(d) means responsive to said outputted amplified RF signal for controlling the amplitude thereof in functional relation to said preselected level and a voltage standing wave ratio (VSWR) load of the RF power amplifier.

1 more element

Dependencies are inferred from the claim text.

Solid state autotune power amplifier

Life of this patent

Solid state autotune power amplifier

Life of this patent

Abstract

Claims10