Abstract: A wireless communication device can include an antenna array configured to receive a plurality of radio frequency (RF) signals, RF circuitry, and digital baseband receive circuitry. The RF circuitry is configured to process the plurality of RF signals received via the antenna array to generate a single RF signal. The digital baseband receive circuitry is coupled to the RF circuitry and is configured to generate a downconverted signal based on the single RF signal, amplify the downconverted signal to generate an amplified downconverted signal, and convert the amplified downconverted signal to generate a digital output signal for processing by a wireless modem. The digital baseband receive circuitry further includes at least a first filtering system configured to filter the downconverted signal prior to amplification.

Abstract: A radio-frequency (RF) amplifier circuit facilites carrier-aggregation (CA) operation in a wireless communication network. A first amplifier subcircuit is coupled to an input node, and a second amplifier subcircuit is coupled to the input node. An amplifier subcircuit selector is to selectively enable operation of the first amplifier subcircuit, the second amplifier subcircuit, or the first and the second amplifier subcircuits together, in response to a selection indication. A reactive coupling network is arranged to selectively adjust the input impedance at the input node in response to the selection indication to reduce the input impedance variation.

Abstract: A wireless communication device can include an antenna configured to sense a radio frequency (RF) signal. The wireless communication device can include signal estimation circuitry configured to generate estimates of amplitude and frequency for unmodulated spurs within the RF signal. The wireless communication device can further include multi-tone generator circuitry coupled to the signal estimation circuitry and configured to generate a composite spur cancellation signal based on the estimates of amplitude and frequency for unmodulated spurs within the RF signal. The wireless communication device can further include adder circuitry configured to subtract the spur cancellation signal from the RF signal to generate a spur cancelled signal.

Abstract: A wireless communication device can include an antenna configured to sense a radio frequency (RF) signal. The wireless communication device can include signal estimation circuitry configured to generate estimates of amplitude and frequency for unmodulated spurs within the RF signal. The wireless communication device can further include multi-tone generator circuitry coupled to the signal estimation circuitry and configured to generate a composite spur cancellation signal based on the estimates of amplitude and frequency for unmodulated spurs within the RF signal. The wireless communication device can further include adder circuitry configured to subtract the spur cancellation signal from the RF signal to generate a spur cancelled signal.

Abstract: A wireless communication device can include an antenna array configured to receive a plurality of radio frequency (RF) signals, RF circuitry, and digital baseband receive circuitry. The RF circuitry is configured to process the plurality of RF signals received via the antenna array to generate a single RF signal. The digital baseband receive circuitry is coupled to the RF circuitry and is configured to generate a downconverted signal based on the single RF signal, amplify the downconverted signal to generate an amplified downconverted signal, and convert the amplified downconverted signal to generate a digital output signal for processing by a wireless modem. The digital baseband receive circuitry further includes at least a first filtering system configured to filter the downconverted signal prior to amplification.

Abstract: A transconductance amplifier having an input terminal for receiving an input signal and an output terminal for communicating an output signal based on the input signal, the transconductance amplifier may include a gain transistor and a variable capacitance. The gain transistor may have a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the output terminal of the transconductance amplifier. The variable capacitance may be coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor.

Abstract: A transconductance amplifier having an input terminal for receiving an input signal and an output terminal for communicating an output signal based on the input signal, the transconductance amplifier may include a gain transistor and a variable capacitance. The gain transistor may have a gate terminal, a first non-gate terminal, and a second non-gate terminal, the first non-gate terminal coupled to the output terminal of the transconductance amplifier. The variable capacitance may be coupled between the gate terminal of the gain transistor and the second non-gate terminal of the gain transistor.

Abstract: The present invention is an RF duplex filter that is used to remove transmit signals from the receive path of a full duplex transceiver. The RF duplex filter includes a notch filter for blocking signals at a transmit frequency and a bandpass filter for enhancing signals at a receive frequency. The notch filter is formed with series resonant elements and the bandpass filter is formed with parallel resonant elements. One embodiment of the present invention may include tunable resonant elements for tuning the notch filter to a transmit frequency, tuning the bandpass filter to a receive frequency, or both. Calibration circuitry may be included in the full duplex receiver for adjusting the tunable resonant elements. The present invention includes a method for calibrating the tunable resonant elements.

Abstract: An air conditioner comprises an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, wherein the outdoor unit comprises a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging a refrigerant, a four-way valve adjacently arranged to the compressor for circulating a refrigerant discharged from the compressor according to a heating cycle or a cooling cycle, a refrigerant detouring path for detouring a refrigerant discharged from the outdoor heat exchanger to the compressor at the time of a defrosting operation, an outdoor expansion device installed in the middle of the detouring path for reducing a pressure of a refrigerant which flows in the refrigerant detouring path, and a heat exchanging device installed in the middle of the detouring path for heat-exchanging between a refrigerant introduced from the outdoor expansion device and a refrigerant discharged from the compressor.

Abstract: A high speed CMOS phase locked loop (PLL) (10) includes a three-state phase detection circuit having a frequency phase detector (12) coupled to a charge pump (14) for monitoring the phase differences between a reference frequency signal and a divided output frequency signal. The PLL can further include a loop filter (16)coupled to the three-state phase detection circuit, a VCO (18) coupled to the output of the loop filter, a VCO buffer (22) coupled to the output of the VCO for providing an output frequency signal, and a dual modulus prescaler (28) having a synchronous counter (27 and 29) using feedback among D flip-flops (30 and 32) for generating the divided output frequency signal.

Abstract: Disclosed are a system for recycling oil in an air conditioner and a method thereof. The system comprises: an oil recycling line connected between a compressor for compressing a refrigerant and an accumulator for dividing a refrigerant into gas and liquid and thereby supplying the gas refrigerant to the compressor, for recycling oil stored in the accumulator to the compressor; an open/close valve installed at the oil recycling line and opening and closing the oil recycling line; and a control unit for controlling the open/close valve and thereby controlling an oil supply from the accumulator to the compressor. According to this, an oil deficiency of the compressor is prevented and thereby a reliability of the compressor is enhanced.

Abstract: An air conditioner comprising an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, wherein the outdoor unit comprises a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging a refrigerant, a four-way valve adjacently arranged to the compressor for circulating a refrigerant discharged from the compressor according to a heating cycle or a cooling cycle, and a refrigerant detouring path for detouring a refrigerant discharged from the outdoor heat exchanger to the compressor at the time of a defrosting operation, thereby performing the defrosting operation without stopping the heating cycle and thus preventing an indoor heating loss.

Abstract: A high speed CMOS phase locked loop (PLL) (10) includes a three-state phase detection circuit having a frequency phase detector (12) coupled to a charge pump (14) for monitoring the phase differences between a reference frequency signal and a divided output frequency signal. The PLL can further include a loop filter (16)coupled to the three-state phase detection circuit, a VCO (18) coupled to the output of the loop filter, a VCO buffer (22) coupled to the output of the VCO for providing an output frequency signal, and a dual modulus prescaler (28) having a synchronous counter (27 and 29) using feedback among D flip-flops (30 and 32) for generating the divided output frequency signal.

Abstract: An air conditioner comprises an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, wherein the outdoor unit comprises a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging a refrigerant, a four-way valve adjacently arranged to the compressor for circulating a refrigerant discharged from the compressor according to a heating cycle or a cooling cycle, a refrigerant detouring path for detouring a refrigerant discharged from the outdoor heat exchanger to the compressor at the time of a defrosting operation, an outdoor expansion device installed in the middle of the detouring path for reducing a pressure of a refrigerant which flows in the refrigerant detouring path, and a heat exchanging device installed in the middle of the detouring path for heat-exchanging between a refrigerant introduced from the outdoor expansion device and a refrigerant discharged from the compressor.

Abstract: An air conditioner comprising an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, wherein the outdoor unit comprises a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging a refrigerant, a four-way valve adjacently arranged to the compressor for circulating a refrigerant discharged from the compressor according to a heating cycle or a cooling cycle, and a refrigerant detouring path for detouring a refrigerant discharged from the outdoor heat exchanger to the compressor at the time of a defrosting operation, thereby performing the defrosting operation without stopping the heating cycle and thus preventing an indoor heating loss.