Abstract: A wireless communication unit (200) comprises a radio frequency (RF) receiver for receiving an RF signal and providing the received RF signal to an off-channel signal detector (218) and a quadrature down conversion mixer circuit comprising at least one dynamic matching mixer stage (226, 228, 250, 252). The off-channel signal detector (218) is arranged to detect whether an off-channel signal level of the received RF signal exceeds a threshold and, in response to determining that the received off-channel RF signal exceeds the threshold, the off-channel signal detector (218) deactivates the at least one dynamic matching mixer stage. Also described is a semiconductor that comprises a receiver, and a method of operation therefor.

Abstract: A wireless communication unit includes a linearised transmitter having a forward path and a feedback path, respectively comprising at least one up-mixer and down-mixer, and forming two loops in quadrature. A phase training signal is applied to the at least one down-mixer in the feedback path in an open loop mode of operation to identify a loop phase adjustment to be applied. At least one of the two loops is switched to a closed loop mode of operation and the loop phase adjustment is applied to at least one up-mixer located in the forward path.

Abstract: A wireless communication unit includes a frequency generation circuit, and a linearised transmitter operably coupled to the frequency generation circuit and having a forward path for routing a signal to be transmitted; and a feedback path, operably coupled to a power amplifier and the forward path for feeding back a portion of the signal to be transmitted. The feedback path and forward path form two loops in quadrature. The frequency generation circuit includes independent phase shift elements arranged to independently phase shift the two loops in quadrature (‘I’ and ‘Q’).

Abstract: An integrated circuit includes a linearizer circuit in which excessive delay is compensated. The linearizer circuit includes a power amplifier, forward and feedback paths, and a microprocessor. A signal from the power amplifier is routed by the forward path to be transmitted while a portion of the signal to be transmitted is routed back to the power amplifier via the feedback path. The microprocessor applies phase training signals to the forward path. The microprocessor uses the phase training signals to determine the amount of delay in the linearizer circuit and alters the frequency position of poles and zeros in the linearizer circuit to compensate for the delay. The gain of the linearizer circuit is also altered by the microprocessor depending on the measured delay.

Abstract: An antenna assembly (10) includes a ground plane formed on a chassis (12) of the radio and the functional knob forming an antenna element (11). The antenna assembly further includes a slot or notch element (14) in the ground plane substantially adjacent to the functional knob and having a length less than ¼ wavelength, and a coaxial cable (13) feeding the antenna element. A shield of the coaxial cable can be directly connected to the ground plane and a center conductor of the coaxial cable can be directly coupled to the functional knob to provide a galvanic connection for narrowband performance or the center conductor can be electromagnetically coupled to the functional knob for wideband performance or both. The antenna assembly can create a zero volume notch type ground excitation.

Abstract: A wireless communication unit (200) comprises a radio frequency (RF) receiver for receiving an RF signal and providing the received RF signal to an off-channel signal detector (218) and a quadrature down conversion mixer circuit comprising at least one dynamic matching mixer stage (226, 228, 250, 252). The off-channel signal detector (218) is arranged to detect whether an off-channel signal level of the received RF signal exceeds a threshold and, in response to determining that the received off-channel RF signal exceeds the threshold, the off-channel signal detector (218) deactivates the at least one dynamic matching mixer stage. Also described is a semiconductor that comprises a receiver, and a method of operation therefor.

Abstract: A linear RF transmitter (100) includes a forward path including a baseband signal combiner (109) and an RF (radio frequency) power amplifier (123), and a linearizing control loop from an output (127) of the RF power amplifier to an input of the combiner (109). A feedback control path (105, 107) of the loop delivers a baseband error control signal to the combiner. The transmitter further includes a test signal generator (102) to apply to the combiner in a closed loop level training mode a test signal comprising a voltage Vin which increases with time in a non-linear manner approaching an asymptotic limit such that in response an output signal produced by the combiner is a voltage Ve which is substantially constant over a period of time.

Abstract: A wireless receiver (100) for receiving and demodulating a frequency modulated RF (radio frequency) signal by a direct conversion procedure, including channels (110, 112) for producing in-phase and quadrature components of a received RF signal, and a processor (123, 133) for periodically estimating an error in at least one of the in-phase and quadrature phase components and for producing a signal for adjustment of at least one of the in-phase and quadrature components to compensate for the detected error, wherein the processor is operable to apply alternatively each of a plurality of different procedures to estimate the error, the procedures including a first procedure which is applied when a signal quality value of the received RF signal is above a threshold value and a second procedure which is applied when a signal quality value of the RF received signal is not above the threshold value.

Abstract: A system and method for performing baseband phase shifting in a Cartesian feedback system includes a forward path for receiving an input baseband signal having two components, and performing up-conversion to output a RF signal; a power amplifier for amplifying the RF signal output from the forward path; and a feedback path for down-converting at least a sample of the output from the power amplifier to a feedback baseband signal comprising two components, and providing the feedback baseband signal to the forward path in order to be summed with the input baseband signal at a summing junction and before the loop filter. The forward path includes a baseband phase shifter for adjusting the baseband signal output from the summing junction in order to compensate for any phase shifts induced in the system.

Abstract: An antenna arrangement (1000) for use in an RF communication terminal including a plurality of resonators (1003, 1005, 1007, 1009) formed from a plurality of conducting wires (1002, 1004, 1008, 1010, 1012) the resonators being operable to provide radio frequency resonances in at least two different operational frequency bands (VHF, UHF, 700/800 MHz, GPS ranges) the wires being mutually adjacent and at least three of the wires having different lengths, and a plurality of radio frequency feed channels (113, 115, 117, 119) each being operably connected to an associated one of the resonators to deliver an RF signal between that resonator and an associated radio.

Abstract: An antenna and methods for manufacturing the antenna is provided. The antenna (100) includes an electrically non-conductive substrate (102). The antenna further includes an electrically conductive strip (104). The electrically conductive strip (104) is wound around the electrically non-conductive substrate (102) so as to form an overlap (120) between adjacent turns of the electrically conductive strip (104), without creating a galvanic connection at the overlap.

Abstract: An antenna assembly (10) includes a ground plane formed on a chassis (12) of the radio and the functional knob forming an antenna element (11). The antenna assembly further includes a slot or notch element (14) in the ground plane substantially adjacent to the functional knob and having a length less than ¼ wavelength, and a coaxial cable (13) feeding the antenna element. A shield of the coaxial cable can be directly connected to the ground plane and a center conductor of the coaxial cable can be directly coupled to the functional knob to provide a galvanic connection for narrowband performance or the center conductor can be electromagnetically coupled to the functional knob for wideband performance or both. The antenna assembly can create a zero volume notch type ground excitation.

Abstract: A Cartesian loop transmitter having isolator eliminator circuitry is presented. The isolator eliminator circuitry includes a set of low pass and wide band pass as well as narrow band pass filters for each of I- and Q-channels, root mean square detectors and dividers connected to a means for comparing. Signals from the means for comparing are received by a microprocessor which controls attenuation setting. The output level of the transmitter is adjusted by generating a small signal measuring an on-channel signal level and a small signal level and then calculating a ratio of the small signal to the on-channel signal. The attenuation setting is increased if the ratio exceeds a defined threshold.

Abstract: A system and method for performing baseband phase shifting in a Cartesian feedback system includes a forward path for receiving an input baseband signal having two components, and performing up-conversion to output a RF signal; a power amplifier for amplifying the RF signal output from the forward path; and a feedback path for down-converting at least a sample of the output from the power amplifier to a feedback baseband signal comprising two components, and providing the feedback baseband signal to the forward path in order to be summed with the input baseband signal at a summing junction and before the loop filter. The forward path includes a baseband phase shifter for adjusting the baseband signal output from the summing junction in order to compensate for any phase shifts induced in the system.

Abstract: A wireless communication unit includes a frequency generation circuit, and a linearised transmitter operably coupled to the frequency generation circuit and having a forward path for routing a signal to be transmitted; and a feedback path, operably coupled to a power amplifier and the forward path for feeding back a portion of the signal to be transmitted. The feedback path and forward path form two loops in quadrature. The frequency generation circuit includes independent phase shift elements arranged to independently phase shift the two loops in quadrature (‘I’ and ‘Q’).

Abstract: A wireless communication unit includes a linearised transmitter having a forward path and a feedback path, respectively comprising at least one up-mixer and down-mixer, and forming two loops in quadrature. A phase training signal is applied to the at least one down-mixer in the feedback path in an open loop mode of operation to identify a loop phase adjustment to be applied. At least one of the two loops is switched to a closed loop mode of operation and the loop phase adjustment is applied to at least one up-mixer located in the forward path.

Abstract: A wireless communication unit (300) comprises a linearised transmitter (325) having a forward path, a power amplifier (324) and a feedback loop, operably coupled to the power amplifier (324) and the forward path. The feedback loop comprises a loop adjustment function (442), and the forward path and feedback loop comprise quadrature circuits. A processor (322) applies a first training signal to a first quadrature circuit loop for routing through the forward path, power amplifier and feedback path to determine at least one first parameter setting of the loop adjustment function (442). The processor (322) also applies a second training signal to a second quadrature circuit loop to determine at least a second parameter setting of the loop adjustment function (442).

Abstract: In accordance with the present invention there is those provided a Cartesian loop transmitter having an isolator eliminator circuitry comprising a set of low pass and band pass filters for each of an I- and Q-channels, root mean square detectors and a divider connected to a comparator are received by a microprocessor which controls attenuation setting. There is also provided a method of adjusting an output level of such transmitter. Said method comprises the step of measuring an on-channel signal level and a noise level and then calculating a ratio of said noise to said on-channel signal. If the ratio exceeds a defined threshold an attenuation of the input attenuators is increased.

Abstract: A wireless receiver (100) for receiving and demodulating a frequency modulated RF (radio frequency) signal by a direct conversion procedure, including channels (110, 112) for producing in-phase and quadrature components of a received RF signal, and a processor (123, 133) for periodically estimating an error in at least one of the in-phase and quadrature phase components and for producing a signal for adjustment of at least one of the in-phase and quadrature components to compensate for the detected error, wherein the processor is operable to apply alternatively each of a plurality of different procedures to estimate the error, the procedures including a first procedure which is applied when a signal quality value of the received RF signal is above a threshold value and a second procedure which is applied when a signal quality value of the RF received signal is not above the threshold value.

Abstract: An antenna arrangement (1000) for use in an RF communication terminal including a plurality of resonators (1003, 1005, 1007, 1009) formed from a plurality of conducting wires (1002, 1004, 1008, 1010, 1012) the resonators being operable to provide radio frequency resonances in at least two different operational frequency bands (VHF, UHF, 700/800 MHz, GPS ranges) the wires being mutually adjacent and at least three of the wires having different lengths, and a plurality of radio frequency feed channels (113, 115, 117, 119) each being operably connected to an associated one of the resonators to deliver an RF signal between that resonator and an associated radio.