Patent application number | Description | Published |
20090075622 | OFFSET CORRECTION FOR PASSIVE MIXERS - A downconversion mixer includes a configurable gate or bulk bias voltage to allow calibration and correction of device offsets. Calibration may be performed on the configurable bias voltages to minimize IM2 distortion in the mixer. The techniques have minimal impact on voltage headroom, impose no requirement for a signal path to be phase-matched with a calibration path, and are particularly well-suited for passive mixers. | 03-19-2009 |
20090130994 | ADJUSTABLE LOCAL OSCILLATOR PATH IN A COMMUNICATION DEVICE WITH A TRANSMITTER - A communication device includes a transmitter and a receiver. The receiver mixes a local oscillator (LO) signal with the received signal to downconvert the received signal to an intermediate frequency (IF). The LO path that feeds the LO signal to the downconverting mixer is controlled based on the transmit power of the transmitter. For high transmit power, the drive of the LO path is increased, thereby increasing the signal-to-noise ratio of the LO signal input into the mixer. For low transmit power levels, the drive to the LO path is decreased, reducing power consumption in the communication device. In this way, receiver path noise due to mixing of the LO phase noise with the self-generated transmitter signal is selectively controlled while incurring lower power consumption penalty. The communication device may be an access terminal configured for communication with a cellular radio network. | 05-21-2009 |
20130259099 | TUNABLE NOTCH FILTER USING FEEDBACK THROUGH AN EXISTING FEEDBACK RECEIVER - A wireless communication device configured for reducing Tx leakage in a receive signal is described. The wireless communication device includes a transceiver chip. The transceiver chip includes a receiver, a feedback receiver and a transmitter. The wireless communication device also includes a Tx leakage signal reduction module. The Tx leakage signal reduction module reuses the feedback receiver. | 10-03-2013 |
20130259102 | TUNABLE NOTCH FILTER USING FEEDBACK THROUGH AN EXISTING FEEDBACK RECEIVER - A wireless communication device configured for reducing Tx leakage in a receive signal is described. The wireless communication device includes a transceiver chip. The transceiver chip includes a receiver, a feedback receiver and a transmitter. The wireless communication device also includes a Tx leakage signal reduction module. The Tx leakage signal reduction module reuses the feedback receiver. | 10-03-2013 |
20130281041 | IMPEDANCE BALANCING FOR POWER SUPPLY REJECTION IN SINGLE-ENDED RECEIVERS - Power supply rejection in a single-ended receiver, through impedance balancing, is described. The single-ended receiver includes a first low noise amplifier and a second low noise amplifier. The single-ended receiver also includes a multi-port coupled transformer that outputs a differential signal. The multi-port coupled transformer includes a first primary coil that is coupled to an output of the first low noise amplifier and a second primary coil. The single-ended receiver also includes balancing impedances at the output of each of the low noise amplifiers. These impedances can be configured such that the on impedance of the first low noise amplifier equals the combined impedance of the off impedance of the second low noise amplifier and the balancing impedance. This balancing of impedances on the first and second primary coils results in power supply rejection of noise and spurious signals. | 10-24-2013 |
20130295870 | SINGLE-ENDED RECEIVER WITH A MULTI-PORT TRANSFORMER AND SHARED MIXER - A single-ended receiver is described. The single-ended receiver includes a multi-port transformer that outputs a differential signal. The multi-port transformer includes a first primary coil that is coupled to an output of a first low noise amplifier. The multi-port transformer also includes a second primary coil that is coupled to an output of a second low noise amplifier. The multi-port transformer further includes a first secondary coil. The single-ended receiver also includes a shared mixer that receives the differential signal from the multi-port transformer. | 11-07-2013 |
20140111252 | THRESHOLD TRACKING BIAS VOLTAGE FOR MIXERS - Bias voltage generators that can generate variable bias voltages for transistors in mixers and other circuits are disclosed. In an exemplary design, an apparatus (e.g., a wireless device or an integrated circuit (IC)) includes at least one transistor and a bias voltage generator. The transistor(s) have a threshold voltage and receive a bias voltage. The bias voltage generator generates the bias voltage based on changes to the threshold voltage of the transistor(s), e.g., due to IC process and/or temperature. In an exemplary design, the bias voltage generator includes a replica transistor that tracks the transistor(s) and an op-amp that provides a gate voltage for the replica transistor. The bias voltage is generated based on the gate voltage. The bias voltage generator may generate the bias voltage (i) to track the threshold voltage of the transistor(s) in a first mode or (ii) based on a fixed voltage in a second mode. | 04-24-2014 |
20140113573 | AMPLIFIERS WITH SHUNT SWITCHES - Amplifiers with shunt switches to mitigate interference are disclosed. In an exemplary design, an apparatus includes an amplifier and a shunt switch. The amplifier has an input operatively coupled to an input/output (I/O) pad of an integrated circuit (IC) chip. The shunt switch grounds the amplifier when the shunt switch is closed. The shunt switch is isolated from the I/O pad and the amplifier input. The amplifier may be a low noise amplifier (LNA) or some other type of amplifier. In an exemplary design, the shunt switch is isolated from the I/O pad by a series switch. The series switch and the shunt switch may be closed when the amplifier is disabled and may be opened when the amplifier is enabled. | 04-24-2014 |
20140139042 | PORT ISOLATION IN SHARED TRANSFORMERS - Techniques for improving performance of a transformer shared amongst a plurality of operating modes. In an aspect, first and second primary windings of a transformer are coupled to an AC ground voltage. Primary windings are mutually coupled to a secondary winding of the transformer. To render the second primary winding inactive, e.g., when operating in a first mode, a switch coupling the second primary winding to the common reference voltage is opened. Similarly, when it is desired to render the first primary winding inactive, e.g., when operating in a second mode, a switch coupling the first primary winding to the common reference voltage is opened. In this manner, the inactive primary winding advantageously does not load the secondary winding. Further aspects provide for, e.g., extending the techniques to more than two modes, and alternative techniques to mutually couple the signal from the primary to the secondary winding. | 05-22-2014 |
20140167862 | ELECTROSTATIC DISCHARGE PROTECTION OF AMPLIFIER CASCODE DEVICES - Exemplary embodiments are directed to providing electrostatic discharge (ESD) protection of a cascode device of an amplifier. In an exemplary embodiment, a transistor is configured to receive a bias voltage and at least one circuit element coupled to the transistor and configured to receive an input voltage via an input pad. Additionally at least one diode can be coupled to a drain of the first transistor and configured to limit a voltage potential at an internal node of the amplifier caused by the input pad. | 06-19-2014 |