An frequency down-converter includes a mixer configured to receive a RF (radio frequency) signal having a first end and a second end and output an intermediate signal comprising a first end and a second end in accordance with a LO (local oscillator) signal having a first end and a second end, wherein the first end and the second end of the LO signal jointly form a two-phase periodic signal of a fundamental frequency approximately equal to a mean frequency of a desired component of the RF signal. The down-converter further includes an opamp (operational amplifier) configured to receive the intermediate signal and output an output signal having a first end and a second end; a first feedback network configured to couple the second end of the output signal to the first end of the intermediate signal; a second feedback network configured to couple the first end of the output signal to the second end of the intermediate signal; and an auxiliary mixer configured to receive the RF signal and provide a supplemental signal added to the output signal in accordance with the LO signal. Preferably, the auxiliary mixer is based on using the same circuit as the mixer but replacing each switch in the mixer with a switch in series with a capacitor.

An RFID receiver (1) comprises an antenna (11) configured to receive a radio signal (20) from an RFID transmitter (2) and to generate an electrical signal (110) from the radio signal (20) received from the RFID transmitter (2). A decoder circuit (10) is connected to the antenna (11) and configured to extract from the electrical signal (110) generated by the antenna (11) data bits encoded in the electrical signal (110). The decoder circuit (10) comprises an analog-to-digital converter (12) connected directly to the antenna (11) and configured to generate a digital input signal (13) from the electrical signal (110) generated by the antenna (11). A bit extractor (14) is connected to the analog-to-digital converter (12) and configured to extract the data bits from the digital input (13) signal generated by the analog-to-digital converter (12).

A high performance low noise amplifier integrated circuit having multiple low noise amplifiers enabling operation over a wide range for frequencies is disclosed. In particular, an auxiliary input is provided to the low noise amplifier integrated circuit that can be routed to one of several low noise amplifiers, each tuned to operate efficiently in different frequency ranges.

Examples of passive diode-based transmitter detuning circuits and low-voltage active diode-based and receiver detuning circuits are provided.

A multi-mixer system includes an amplifier module and a plurality of channels. The amplifier module is arranged for receiving signals from an antenna or antenna arrays to generate a plurality of radio frequency (RF) input signals. The plurality of channels are coupled to the amplifier module, wherein the plurality of channels receive the RF input signals, respectively, and each of the channels includes a mixer for mixing one of the RF input signals with a local oscillating signal to generate a mixed signal. In addition, at least one of the channels includes an interference reduction circuit positioned between the amplifier module and the mixer.

This invention presents a method and apparatuses for wireless networking comprising one or more BS with N.sub.bs antennas; two or more SCs in the range of a BS where a SC has N.sub.sc antennas, uses N.sub.sc1N.sub.sc antennas for communication with a BS and uses N.sub.sc2N.sub.sc antennas for communication with one or more UEs; at the same time a BS transmitting DL signals to K SCs using multi-user transmit BF in a frequency channel, a SC simultaneously transmitting DL signals to one or more UEs in its range using the same frequency channel; and, at the same time a BS receiving UL signals from K SCs using multi-user receive BF in a frequency channel, a SC simultaneously receiving UL signals from one or more UEs in its range using the same frequency channel. Furthermore, beamforming using antennas on the SCs is performed to reduce the inter-SC interferences.

Disclosed is a noise filter. The noise filter includes an input port to receive an analog signal. The noise filter further includes a multiplexer coupled to the input port. The multiplexer separates the analog signal into a plurality of frequency bands. The frequency bands include a high frequency band and a low frequency band. The noise filter also includes a low-band variable attenuator coupled to the multiplexer. The low-band variable attenuator adjustably attenuates the low frequency band relative to the high frequency band.

A mobile device may be configured to perform concurrent Satellite Positioning System and communication system operation, e.g. enabling an SPS receiver to continue to receive SPS signals in frequency bands that are interfered with due to aggressor transmission signals. A controllable filter, such as a selectable and/or tunable notch or lowpass filter is used to reject the aggressor transmission signals. The controllable filter may also attenuate some, but not all, frequencies in the SPS L1 band. To avoid losing complete access to these filtered SPS signal frequencies, the controllable filter is controlled, e.g., selected or tuned to these frequencies only when the aggressor transmission signal is active, and is otherwise turned off or tuned away from the SPS signal frequencies.

An RF filter comprising a resonator element and a polymer composition is provided. The polymer composition contains an aromatic polymer and has a melting temperature of about 240? C. or more. The polymer composition exhibits a dielectric constant of about 5 or less and dissipation factor of about 0.05 or less at a frequency of 10 GHz.

A semiconductor device includes a semiconductor chip. The semiconductor chip includes: a switching-type DC-DC converter; a pad for receiving a high frequency signal from an antenna; a balun connected to the pad and configured with a coil to output a differential signal based on the high frequency signal; an internal circuit driven by an output voltage of the DC-DC converter to process the differential signal output from the balun; and a ground voltage line that couples the internal circuit to a ground voltage source. The ground voltage line includes a first partial ground voltage line, and a second partial ground voltage line arranged to face the first partial ground voltage line with the balun interposed therebetween.