Diode loaded feed-forward radio frequency amplifier power control

Claim 2

A selective call receiver including a radio frequency amplifier having an output power level that is controllable in an unconditionally stable manner, the selective call receiver comprising: a loading diode coupled to an output of the radio frequency amplifier; and a feed-forward load control coupled to an input of the radio frequency amplifier for detecting an input signal strength and regulating conduction of a current through the loading diode in response to the input signal strength substantially reaching or exceeding a predetermined activation threshold corresponding with a predetermined input signal strength and a maximum output power level, the current causing an impedance of the loading diode to vary in a manner that causes the output power level to remain substantially constant.

Claim 3

The selective call receiver according to claim 1 wherein the feed-forward load control comprises: a single ended input, single ended output, differential amplifier, the feed-forward load control operating: in a first state when the input signal level received at the radio frequency amplifier is below the predetermined activation threshold such that the differential halves are biased in a first asymmetric direction resulting in no conduction of the current through the loading diode, thus allowing the output power level to substantially track the received input signal level; and in a second state when the input signal level received at the radio frequency amplifier substantially reaches or exceeds the predetermined signal overload level such that the differential halves are biased in a second asymmetric direction resulting in conduction of the current through the loading diode, thus effecting adjustment of the power gain of the radio frequency amplifier to maintain a substantially constant radio frequency amplifier output power level.

Claim 4

The selective call receiver according to claim 1 wherein the radio frequency amplifier, the loading diode, and the feed-forward load control are fabricated in an integrated circuit.

Claim 5

The selective call receiver according to claim 3 wherein the integrated circuit is fully operational when powered by a supply voltage of substantially one volt DC.

Claim 6

The selective call receiver according to claim 1 further comprising: receiver including the radio frequency amplifier having the output power level that is controllable; a demodulator coupled to the receiver for recovering the received signal and providing an information signal; a decoder for correlating a recovered address contained within the information signal with a predetermined address corresponding to the selective call receiver, and responsive to said recovered and predetermined addresses substantially correlating, generating a detection indicating selection of the selective call receiver; and a support circuit to process information recovered from the information signal for presentation in response to the detection indicating selection of the selective call receiver.

Claim 7

A selective call receiver, comprising: a receiver including a radio frequency amplifier having an output power level that is controllable, the receiver operating to provide a received signal, the receiver comprising: a loading diode coupled to an output of the radio frequency amplifier; and a feed-forward load control coupled to an input of the radio frequency amplifier for detecting an input signal strength and regulating conduction of a current through the loading diode in response to the input signal strength substantially reaching or exceeding a predetermined activation threshold corresponding with a predetermined input signal strength and a maximum output power level, the current causing an impedance of the loading diode to vary in a manner that causes the output power level to remain substantially constant; a demodulator coupled to the receiver for recovering the received signal and providing an information signal; a decoder for correlating a recovered address contained within the information signal with a predetermined address corresponding to the selective call receiver, and responsive to said recovered and predetermined addresses substantially correlating, generating a detection indicating selection of the selective call receiver; and a support circuit to process information recovered from the information signal for presentation in response to the detection indicating selection of the selective call receiver.

Claim 8

A selective call receiver, comprising: a receiver including a radio frequency amplifier having an output power level that is controllable, the receiver operating to provide a received signal, the receiver comprising: a loading diode coupled to an output of the radio frequency amplifier; and a feed-forward load control coupled to an input of the radio frequency amplifier for detecting an input signal strength and regulating conduction of a current through the loading diode in response to the input signal strength substantially reaching or exceeding a predetermined activation threshold corresponding with a predetermined input signal strength and a maximum output power level, the current causing an impedance of the loading diode to vary in a manner that causes the output power level to remain substantially constant; a demodulator coupled to the receiver for recovering the received signal and providing an information signal; a decoder for correlating a recovered address contained within the information signal with a predetermined address corresponding to the selective call receiver, and responsive to said recovered and predetermined addresses substantially correlating, generating a detection indicating selection of the selective call receiver; and a support circuit to process information recovered from the information signal for presentation in response to the detection indicating selection of the selective call receiver.

Claim 9

The selective call receiver according to claim 6 wherein the feed-forward load control comprises: a single ended input, single ended output, differential amplifier, the feed-forward load control operating: in a first state when the input signal level received at the radio frequency amplifier is below the predetermined activation threshold such that the differential halves are biased in a first asymmetric direction resulting in no conduction of the current through the loading diode, thus allowing the output power level to substantially track the received input signal level; and in a second state when the input signal level received at the radio frequency amplifier substantially reaches or exceeds the predetermined signal overload level such that the differential halves are biased in a second asymmetric direction resulting in conduction of the current through the loading diode, thus effecting adjustment of the power gain of the radio frequency amplifier to maintain a substantially constant radio frequency amplifier output power level.

Claim 10

The selective call receiver according to claim 6 wherein the radio frequency amplifier, the loading diode, and the feed-forward load control are fabricated in an integrated circuit.

Claim 11

The selective call receiver according to claim 8 wherein the integrated circuit is fully operational when powered by a supply voltage of substantially one volt DC.