System and method for adaptive antenna impedance matching
First Claim
1. A wireless transceiver with automatic antenna impedance matching, the transceiver comprising:
- a transmitter circuit configured to generate a phase-amplitude modulated signal based on a phase-amplitude modulation signal;
a receiver circuit configured to downconvert one or more input signals and to produce digital baseband signals from downconverted signals; and
an antenna system configured to couple the transmitter circuit and the receiver circuit to an antenna, the antenna system comprising a coupling circuit configured to couple a transmitter signal reflected from the antenna to the receiver circuit and further comprising an adjustable matching network between the antenna and at least the transmitter circuit; and
a baseband processor configured to process digital signals produced by the receiver circuit from the reflected transmitter signal to;
compensate the reflected transmitter signal using the phase-amplitude modulation signal to remove phase-amplitude modulation components in the reflected transmitter signal;
characterize an impedance mismatch between the transmitter circuit and the antenna based on the compensated reflected transmitter signal; and
control the adjustable matching network based on the characterization.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and apparatus are disclosed for automatically adjusting antenna impedance match in a wireless transceiver employing phase-amplitude modulation. According to some embodiments of the invention, a wireless transceiver comprises a transmitter circuit and a receiver circuit connected to the antenna by a transmit/receive duplexer. An electronically adjustable matching network is located between the transmitter output and the antenna. To control the adjustable matching network, a directional coupler is located between the transmitter output and the matching network to separate transmit signals reflected from the antenna system, including the antenna, the matching network and the T/R duplexer. The reflected transmit signals are routed to the receiver circuit, which digitizes the reflected signal and determines an antenna reflection coefficient based on the digitized reflected signal and the modulation signal used to create the transmit signal. The complex antenna reflection coefficient is used to determine any adjustment needed to the antenna matching network.
-
Citations
24 Claims
-
1. A wireless transceiver with automatic antenna impedance matching, the transceiver comprising:
-
a transmitter circuit configured to generate a phase-amplitude modulated signal based on a phase-amplitude modulation signal; a receiver circuit configured to downconvert one or more input signals and to produce digital baseband signals from downconverted signals; and an antenna system configured to couple the transmitter circuit and the receiver circuit to an antenna, the antenna system comprising a coupling circuit configured to couple a transmitter signal reflected from the antenna to the receiver circuit and further comprising an adjustable matching network between the antenna and at least the transmitter circuit; and a baseband processor configured to process digital signals produced by the receiver circuit from the reflected transmitter signal to; compensate the reflected transmitter signal using the phase-amplitude modulation signal to remove phase-amplitude modulation components in the reflected transmitter signal; characterize an impedance mismatch between the transmitter circuit and the antenna based on the compensated reflected transmitter signal; and control the adjustable matching network based on the characterization. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A method for automatically adjusting an antenna impedance match in a wireless transceiver, the method comprising:
-
transmitting, via an antenna, a signal generated from a phase-amplitude modulation signal; coupling a reflected portion of the signal from the antenna to a receiver circuit; downconverting the reflected portion of the signal, using the receiver circuit, to obtain digital baseband samples; and processing the digital baseband samples to; compensate the digital baseband samples to remove phase-amplitude modulation components present in the reflected portion of the signal; characterize an antenna impedance mismatch based on the compensated digital baseband samples; and control the adjustable matching network based on the characterization. - View Dependent Claims (19, 20, 21, 22, 23, 24)
-
Specification