RF circuit with control unit to reduce signal power under appropriate conditions
First Claim
1. An RF circuit driven by a supply voltage, comprising:
- a power amplifier operable to receive an RF input signal and to produce an RF output signal;
a detector operable to generate a detector signal having a current indicative of a power of the RF output signal; and
an offset unit operable to generate an offset signal having a current indicative of a low supply voltage condition in which the supply voltage is below a specified threshold;
wherein the power of the RF output signal is controlled at least in part by a control signal indicative of a control signal current, wherein the control signal current is equal to a sum of the detector signal current and the offset signal current.
22 Assignments
0 Petitions
Accused Products
Abstract
A disclosed RF circuit includes a power amplifier that produces an RF output signal, a detector to generate a detector signal indicative of a power of the RF output signal, and an offset unit to produce an offset signal that indicates low supply voltage conditions. The power of the RF output signal is reduced, at least in part, by a control signal reflecting a combination of the detector signal and the offset signal. The circuit may include a transmitter to provide an RF input signal to the power amplifier. The transmitter may receive the control signal and adjust a power of the RF input signal based on the control signal. The detector may produce a control current indicative of the RF output signal power. The offset unit produces the offset signal based on a difference between the supply voltage and a nominal supply voltage value.
61 Citations
22 Claims
-
1. An RF circuit driven by a supply voltage, comprising:
-
a power amplifier operable to receive an RF input signal and to produce an RF output signal; a detector operable to generate a detector signal having a current indicative of a power of the RF output signal; and an offset unit operable to generate an offset signal having a current indicative of a low supply voltage condition in which the supply voltage is below a specified threshold; wherein the power of the RF output signal is controlled at least in part by a control signal indicative of a control signal current, wherein the control signal current is equal to a sum of the detector signal current and the offset signal current. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A transmitter system suitable for use in an RF application, comprising:
-
a power amplifier operable to receive an RF input signal and produce an RF output signal, said RF output signal characterized by an RF output signal power and wherein the power amplifier is configured to receive a supply voltage based on a battery voltage from a battery; a control unit operable to produce a control signal; and a transmitter operable to change the RF output signal power by changing the RF input signal and further operable to control the RF output signal power based on said control signal; wherein the control signal is indicative of a control signal current provided to a control node of the control unit and wherein the control node sources a current of a detector signal, indicative of a power of the RF output signal, and a current of an offset signal, indicative of the battery voltage. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. An RF circuit, comprising:
-
a power amplifier operable to receive a supply voltage produced by a battery and further operable to produce an RF output signal; and a control unit operable to produce a control signal indicative of a control signal current that includes an offset component indicative of the supply voltage and a power component indicative of the power of the RF output signal wherein the control unit includes a control node that sinks the control signal current and sources the offset component and the power component; wherein the RF circuit is operable to control the RF output signal power based at least in part on the control signal. - View Dependent Claims (18, 19, 20, 21, 22)
-
Specification