Abstract:
A method and apparatus mitigates spurious transmissions. An offset local oscillator signal is generated that is at a frequency that is offset from a nominal transmit channel carrier frequency by a spurious mitigation offset. An information signal is generated that comprises a series of modulation symbols and has a transmission bandwidth at baseband. A configured offset information signal is generated from the information signal, wherein the spectrum of the configured offset information signal is offset from DC by a channel configuration offset, and is further offset by a negative of the spurious mitigation offset. The offset local oscillator signal and the configured offset information signal are combined using a mixing technique. The spurious mitigation offset is zero when a spurious condition does not exist and is non-zero when the spurious condition does exist.
Abstract:
A transmitter circuit (200, 400, 510) and method reduces amplitude modulation distortion in an amplifier (210). The transmitter circuit (200, 400, 510) includes a power control error data generator (230), a feedforward predistortion data generator (240), feedforward adder logic (250) and the amplifier (210). The power control error data generator (230) receives amplitude modulation data (252) and an RF coupled output signal (254) and, in response, produces power control error data (256). The feedforward predistortion data generator (240) receives the amplitude modulation data (252) and, in response, produces feedforward predistortion data (258). The feedforward adder logic (250) receives the power control error data (256) and the feedforward predistortion data (258) and, in response, produces power control data (260). The amplifier (210) receives the power control data (260) and an RF input signal (261) and, in response, produces an RF output signal (262), such that the power control data (260) reduces amplitude modulation distortion in the RF output signal (262).
Abstract:
A transmission line coupler (115) for a transmitter output signal (123) generated by an RF signal amplifier (103) includes a through-path transmission line (201) and a coupled-path transmission line (202) electromagnetically coupled thereto by multiple serpentine-like portions (such as portions 641, 642, 643 and 644 in FIG. 6 ), which are disposed on opposite sides of the through-path transmission line (201) for enhancing coupling sensitivity and eliminating degradation in the amount of coupling due to variations in the transmission line plating registration. Offset portions (641, 643) on one side of the through-path transmission line (201) provide substantially the same amount of coupling as the offset portions (642,643) on the other side of the through-path transmission line (201). The transmission line coupler (115) is embedded in the output match of the final amplifier (103) and includes complex impedances (212 and 210, 222) at each port of the coupled-path transmission line (202) for substantially eliminating undesired reflections. The coupled port of the coupled-path transmission line (202) is coupled by an inductor (211) to a hot-carrier diode (206) for enhancing the detection sensitivity thereof.
Abstract:
A method (700) and apparatus (600) optimize resource block based transmitter operation in a wireless communication device. The method can include receiving (720) a radio resource assignment including a particular resource block allocation. The method can include configuring (730) a wireless communication transceiver for the particular resource block allocation. The method can include degrading (740) power amplifier distortion of the wireless communication transceiver based on the particular resource block allocation. The power amplifier distortion can be a measure of a deviation of the power amplifier output in an analysis domain from an ideal linear amplifier.
Abstract:
A method and apparatus can cut back power in a simultaneous dual frequency band call. The method may operate a dual frequency band transmit device. The method may include determining if a transmit frequency in a first frequency band from the device combined with a transmit frequency in a second frequency band from the device causes receiver desensitization at the device. The method may include determining if the transmit power in the first frequency band is above a threshold power. The method may include reducing maximum transmit power in the second frequency band by an amount proportional to transmit power in the first frequency band and transmit signal bandwidth in the second frequency band in only the portion of the second frequency band where a resultant frequency component can cause desensitization.
Abstract:
A method (600) and devices for enhancing the performance of one or more antennas (440) is provided. A control circuit (104) assesses performance of an antenna (101) in a plurality of bands, such as a receive band and a transmit band. The control circuit (104) can then adjust an adjustable impedance matching circuit (103) coupled to the antenna (101) to improve the efficiency of the antenna (101) in the selected band and can adjust a resonance of the antenna (101) to further improve an efficiency of the antenna (101) in the selected band. Operating parameters for the antenna (101) can be selected from one or more multi-dimensional lookup tables (120) where the parameters are indexed both to a first operating band (702) and a second operating band (703).
Abstract:
An offset transmission line coupler (115) for a transmitter output signal (123) generated by an RF signal amplifier (103) includes a through-path transmission line (201) and a coupled-path transmission line (202) electromagnetically coupled thereto by multiple serpentine-like portions (such as portions 641,642, 643 and 644 in FIG. 6), which are disposed on opposite sides of the through-path transmission line (201) for enhancing coupling sensitivity and eliminating degradation in the amount of coupling due to variations in the transmission line plating registration. Offset portions (641,643) on one side of the through-path transmission line (201) provide substantially the same amount of coupling as the offset portions (642,643) on the other side of the through-path transmission line (201). The offset portions (641, 642, 643, 644) are offset substantially the same distance from the through-path transmission line (201), and the total length of the offset portions (641, 644) on one side are equal to the total length of the offset portions (642, 643) on the other side of the through-path transmission line (201).