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.

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 terminal (200) and method for operation thereof for use in a wireless communication system (100), the terminal including a plurality of antennas (215, 235, 255) and a plurality of receiver chains (217, 237, 257) each including an associated one of the antennas, the terminal being operable to receive a signal including a plurality of time divided portions including a first portion (303) and a second portion (304), characterised in that the terminal is operable in a manner such each of the plurality of receiver chains is active when the first portion of the signal is being received and at least one of the receiver chains is inactive when the second portion of the signal is being received.

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 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: 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.

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 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 said means for comparing 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 generating a small signal measuring an on-channel signal level and said small signal level and then calculating a first ratio of said small signal to said on-channel signal. If said first ratio exceeds a defined threshold said attenuation setting is increased.

Abstract: A RFPA (radio frequency power amplifier) circuit (150) which includes a RFPA (101), a supply voltage source (104), means (155) for applying to the RFPA a gain control bias voltage and a feedback control loop (156) for adjusting a voltage applied to the RFPA, the feedback control loop including a sampler (107) for sampling an output of the RFPA, a RF detector (109) for detecting a level of RF power sampled by the sampler, a comparator (115) for comparing an output signal from the RF detector with a reference signal, an integrator (117) for integrating an output signal of the comparator and a voltage regulator (151) having a first input from the integrator and a second input from the supply voltage source and an output connected to the RFPA, the regulator being operable to apply to the RFPA a supply voltage adjusted in response to an input signal from the integrator.

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: An automatic gain control (AGC) method and circuit (10) within a receiver uses a digital state machine (26) to implement the AGC function. independent from interaction with a host processor (36) and for multiple modulation protocols without duplicating circuitry. Modulation protocol and parameters for any of various gain responses are stored in a register (29). Multiple states, each corresponding to a predetermined range of RF input signal strength, are stored in the register. Each state contains parameters that determine a gain control signal for controlling a variable gain amplifier (16). The states are independent and may be selectively disabled to create asymmetric responses. Within any state, an adaptable number of iterations may be set to implement a different update rate or step size after a predetermined number of closed loop gain change iterations has not resulted in a transition to a state that represents a desired output gain.

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: A RFPA (radio frequency power amplifier) circuit (150) which includes a RFPA (101), a supply voltage source (104), means (155) for applying to the RFPA a gain control bias voltage and a feedback control loop (156) for adjusting a voltage applied to the RFPA, the feedback control loop including a sampler (107) for sampling an output of the RFPA, a RF detector (109) for detecting a level of RF power sampled by the sampler, a comparator (115) for comparing an output signal from the RF detector with a reference signal, an integrator (117) for integrating an output signal of the comparator and a voltage regulator (151) having a first input from the integrator and a second input from the supply voltage source and an output connected to the RFPA, the regulator being operable to apply to the RFPA a supply voltage adjusted in response to an input signal from the integrator.

Abstract: A device for linear transmitter (150) with improved loop gain stabilization. The linear transmitter (150) includes a main amplifier loop (178) and an auxiliary loop (176). The device includes an adjustable device (159), connected within the main amplifier feedback loop (178) and further connected to the auxiliary loop (176). The adjustable driver (159) receives an input signal from main amplifier feedback loop (178), amplifies it in accordance with a gain control signal received from the auxiliary loop (176) and provides the amplified signal to main amplifier feedback loop (178).

Abstract: An automatic gain control (AGC) circuit including: a forward transmission path (214) having applied at its input an input RF signal and to provide at its output an output signal; a variable gain AGC amplifier (210) in the forward transmission path for processing the input RF signal, which amplifier has a control input 240 and is responsive to a control signal applied at its control input to vary its gain; a feedback loop (220 to 240), coupled from the output of the forward transmission path and to the control input of the AGC amplifier; an integrator (230, 232), coupled to the control input of the amplifier; a voltage source (234), coupled to the integrator and to the control input of the amplifier; and a further variable gain device (215) for varying the gain or attenuation of a signal applied to the control input of the AGC amplifier.