Transmitter power amplifier ramping method
AssigneeKoninklijke Philips Electronics N.V.
InventorRISHI MOHINDRA
Life of this patent
Estimating the term…
Abstract
A method for reducing frequency glitches in a digital transceiver due to power amplifier input impedance variations. According to the method, the power amplifier is switched on after the end of a prior packet reception period and before a new packet transmission begins. Instead of ramping the power amplifier gain, the method ramps the modulation signals. As a consequence, any VCO frequency transients that may result from turning on the power amplifier have an opportunity to decay before the new packet transmission is initiated. This technique effectively isolates the transmitter power amplifier from the frequency synthesizer VCO to facilitate fast switching transceiver operation.
Claims12
A transceiver, comprising:
- a receiver;
- a transmitter including a power amplifier, and a pair of up-converter mixers;
- a frequency synthesizer including a voltage controlled oscillator (VCO);
- a controller for isolating the power amplifier and the VCO, comprising:
- means for switching on the power amplifier after an end of a prior packet reception period, and
- means for ramping modulation signals supplied to the up-converter mixers upon initiation of a new packet transmission.
A transceiver for use in a wireless local area network (WLAN), comprising:
- a radio circuit including a power amplifier, a pair of up-converter mixers, and a frequency synthesizer;
- a processor coupled to the radio circuit and including means for generating modulation signals that are supplied to the up-converter mixers;
- and
- a controller for switching on the power amplifier at an end of a prior packet reception period and for ramping the modulation signals supplied to the up-converter mixers upon initiation of a new packet transmission.
A transceiver, comprising:
- a receiver;
- a transmitter including a power amplifier, and a pair of up-converting mixers;
- a frequency synthesizer including a voltage controlled oscillator;
- a controller for isolating the power amplifier in advance of packet transmission;
- and
- means for ramping modulation signals supplied to the up-converter mixers upon initiation of a new packet transmission.
Dependencies are inferred from the claim text.