Abstract: Within a receiver, the frequency of a comparison reference clock signal supplied to a fractional-N Phase-Locked Loop (PLL) is dynamically changed such that undesirable reciprocal mixing of reference spurs with known jammers (for example, transmit leakage) is minimized. As the transmit channel changes within a band, and as the transmit leakage frequency changes, a circuit changes the frequency of the comparison reference clock signal such that reference spurs generated by the PLL are moved in frequency so that they do not reciprocally mix with transmitter leakage in undesirable ways. In a second aspect, the PLL is operable either as an integer-N PLL or a fractional-N PLL. In low total receive power situations, the PLL operates as an integer-N PLL to reduce receiver susceptibility to fractional-N spurs. In a third aspect, jammer detect information is used to determine the comparison reference clock signal frequency.

Abstract: A radio frequency package on package (PoP) circuit is described. The radio frequency package on package (PoP) circuit includes a first radio frequency package. The first radio frequency package includes radio frequency components. The radio frequency package on package (PoP) circuit also includes a second radio frequency package. The second radio frequency package includes radio frequency components. The first radio frequency package and the second radio frequency package are in a vertical configuration. The radio frequency components on the first radio frequency package are designed to reduce the effects of ground inductance.

Abstract: A low-power diversity receiver includes at least two receive paths, each of which is designated as a primary or secondary receive path. A primary receive path is compliant with system requirements (e.g., IS-98D requirements). A secondary receive path is not fully compliant with the system requirements and is designed for lower power, less area, and lower cost than the primary receive path. For a multi-antenna receiver, the two receive paths may be used to simultaneously process two received signals from two antennas. For a single-antenna receiver, either the primary or secondary receive path is selected, e.g., depending on whether or not large amplitude “jammers” are detected, to process a single input signal from one antenna. The receiver may include additional receive paths for additional frequency bands and/or GPS.

Abstract: A tunable multi-band receiver supporting operation on a plurality of frequency bands is disclosed. In an exemplary design, the tunable multi-band receiver includes an antenna tuning network, a tunable notch filter, and at least one low noise amplifier (LNA). The antenna tuning network tunes an antenna (e.g., a diversity antenna) to a receive band in a plurality of receive bands. The tunable notch filter is tunable to a transmit band in a plurality of transmit bands and attenuates signal components in the transmit band. One LNA among the at least one LNA amplifies an output signal from the tunable notch filter. The tunable multi-band receiver may further include one or more additional tunable notch filters to further attenuate the signal components in the transmit band.

Abstract: A modem is described. The modem includes a transmitter. The transmitter includes a digital pre-distortion module and a power amplifier. The modem also includes one or more selected shared receivers. The one or more selected shared receivers generate a feedback signal for the digital pre-distortion module. The modem further includes a feedback switch. The feedback switch selectively couples the one or more selected shared receivers to an output of the transmitter.

Abstract: A method for reducing power consumption on a wireless communication device is described. The wireless communication device includes a first stage active filter and a second stage active filter. A condition measurement is obtained that includes a signal measurement condition. If it is determined that the condition measurement is above a threshold, the second stage active filter is bypassed.

Abstract: A method for reducing power consumption on a wireless communication device is described. The wireless communication device includes a first stage active filter and a second stage active filter. A condition measurement is obtained that includes a signal measurement condition. If it is determined that the condition measurement is above a threshold, the second stage active filter is bypassed.

Abstract: Techniques for controlling operation of control loops in a receiver are described. The operation of at least one control loop is modified in conjunction with a change in operating state, which may correspond to a change in linearity state, gain state, operating frequency, antenna configuration, etc. A change in linearity state may occur when jammers are detected and may cause bias current of analog circuit blocks to be adjusted. The at least one control loop to be modified may include a DC loop, an AGC loop, etc. The operation of a control loop may be modified by disabling the control loop or changing its time constant prior to changing operating state, waiting a predetermined amount of time to allow the receiver to settle, and enabling the control loop or restoring its time constant after waiting the predetermined amount of time.

Abstract: A system and method of conducting wireless communications between a wireless communication device (WCD) and both a first network (e.g., IS-2000) supporting voice and data services and a second network (e.g., IS-856) supporting packet data services. The method comprises providing the WCD with a primary transceiver and a secondary receiver for conducting wireless communications in a spatial diversity for the second network traffic or broadcast; disabling the secondary receiver and spatial diversity before a paging slot or 1x system acquisition and synchronization attempts; tuning the secondary receiver to a first network carrier frequency to perform first network activities; and retuning the secondary receiver to a second network carrier frequency for spatial diversity after performing the first network activities. The first network activities may include pilot set maintenance, overhead message maintenance, page match detection, or 1x system acquisition and synchronization attempts.

Abstract: Techniques for generating local oscillator (LO) signals are described. In one design, an apparatus may include a deskew circuit and a divider circuit. The deskew circuit may receive a differential input oscillator signal having timing skew and provide a differential output oscillator signal having reduced timing skew. The differential input oscillator signal may include first and second input oscillator signals, and the differential output oscillator signal may include first and second output oscillator signals. In one design, the deskew circuit may include first and second variable delay circuits that receive the first and second input oscillator signals, respectively, and provide the first and second output oscillator signals, respectively. Each output oscillator signal may have an adjustable delay selected to reduce timing skew. The divider circuit may divide the differential output oscillator signal in frequency and provide differential I and Q divided signals, which may be used to generate LO signals.

Abstract: An integrated circuit for achieving power reduction in a transceiver may include a jammer detector that determines an interference level corresponding to a received signal, and a transmit power detector that determines a required transmit power level for a transmitted signal. The integrated circuit may also include at least one of the following: a process monitor that determines process corners of components within the receiver and/or the transmitter, and a temperature monitor that determines a temperature of the receiver and/or the transmitter. The integrated circuit may also include a state machine. The state machine may transition the receiver from a high linearity mode to a low linearity mode if a set of operating conditions is satisfied. Similarly, the state machine may transition the transmitter from a high power mode to a low power mode if a set of operating conditions is satisfied.

Abstract: Techniques for operating a receiver to linearity performance and higher receive signal to noise ratio are described. The receiver includes one or more circuit blocks, e.g., a low noise amplifier (LNA), having discrete gain states. The gain states are selected based on switch points, with each switch point indicating a specific received signal level at which to switch from one gain state to another gain state. The switch points may be dynamically selected based on channel conditions, which may be characterized by the presence or absence or strength or frequency of jammers. A first set of switch points may be selected when jammers are detected, and a second set of switch points may be selected when jammers are not detected. The gain states are selected in accordance with the set of switch points selected for use.

Abstract: A modem is described. The modem includes a transmitter. The transmitter includes a digital pre-distortion module and a power amplifier. The modem also includes one or more selected shared receivers. The one or more selected shared receivers generate a feedback signal for the digital pre-distortion module. The modem further includes a feedback switch. The feedback switch selectively couples the one or more selected shared receivers to an output of the transmitter.

Abstract: A tunable multi-band receiver supporting operation on a plurality of frequency bands is disclosed. In an exemplary design, the tunable multi-band receiver includes an antenna tuning network, a tunable notch filter, and at least one low noise amplifier (LNA). The antenna tuning network tunes an antenna (e.g., a diversity antenna) to a receive band in a plurality of receive bands. The tunable notch filter is tunable to a transmit band in a plurality of transmit bands and attenuates signal components in the transmit band. One LNA among the at least one LNA amplifies an output signal from the tunable notch filter. The tunable multi-band receiver may further include one or more additional tunable notch filters to further attenuate the signal components in the transmit band.

Abstract: A system and method of improving wireless communications between a wireless communication device and both a first network supporting voice and data services and a second network supporting packet data services. The method comprises providing the WCD with a primary transceiver and a secondary receiver for conducting wireless communications in both a simultaneous-mode and a hybrid-mode; performing simultaneous-mode-to-hybrid-mode and hybrid-mode-to-simultaneous-mode transitions based on a performance metric; and evaluating the performance metric to determine whether to perform the mode transitions. In the simultaneous-mode, the primary transceiver conducts wireless communications in the second network and the secondary receiver conducts wireless communications in the first network. In the hybrid-mode, the primary transceiver use is time multiplexed during all of the first and second networks communications combinations.

Abstract: Techniques for operating two receivers to receive data and paging from two systems are described. A primary receiver is associated with better performance than a secondary receiver under poor RF conditions. The two receivers may be operated in either a hybrid mode in which the primary receiver is used to receive paging or a simultaneous mode in which the second receiver is used to receive paging. One of the modes may be selected for use based on RF conditions, received power, demodulation metrics, and/or other criteria. In one design, a mode is selected based on the received power and one or more thresholds. In another design, the hybrid mode is selected for poor RF conditions and, for good RF conditions, the hybrid or simultaneous mode is selected based on received power.

Abstract: Techniques for generating local oscillator (LO) signals are described. In one design, an apparatus may include a deskew circuit and a divider circuit. The deskew circuit may receive a differential input oscillator signal having timing skew and provide a differential output oscillator signal having reduced timing skew. The differential input oscillator signal may include first and second input oscillator signals, and the differential output oscillator signal may include first and second output oscillator signals. In one design, the deskew circuit may include first and second variable delay circuits that receive the first and second input oscillator signals, respectively, and provide the first and second output oscillator signals, respectively. Each output oscillator signal may have an adjustable delay selected to reduce timing skew. The divider circuit may divide the differential output oscillator signal in frequency and provide differential I and Q divided signals, which may be used to generate LO signals.

Abstract: An integrated circuit for achieving power reduction in a transceiver may include a jammer detector that determines an interference level corresponding to a received signal, and a transmit power detector that determines a required transmit power level for a transmitted signal. The integrated circuit may also include at least one of the following: a process monitor that determines process corners of components within the receiver and/or the transmitter, and a temperature monitor that determines a temperature of the receiver and/or the transmitter. The integrated circuit may also include a state machine. The state machine may transition the receiver from a high linearity mode to a low linearity mode if a set of operating conditions is satisfied. Similarly, the state machine may transition the transmitter from a high power mode to a low power mode if a set of operating conditions is satisfied.

Abstract: Within a receiver, the frequency of a comparison reference clock signal supplied to a fractional-N Phase-Locked Loop (PLL) is dynamically changed such that undesirable reciprocal mixing of reference spurs with known jammers (for example, transmit leakage) is minimized. As the transmit channel changes within a band, and as the transmit leakage frequency changes, a circuit changes the frequency of the comparison reference clock signal such that reference spurs generated by the PLL are moved in frequency so that they do not reciprocally mix with transmitter leakage in undesirable ways. In a second aspect, the PLL is operable either as an integer-N PLL or a fractional-N PLL. In low total receive power situations, the PLL operates as an integer-N PLL to reduce receiver susceptibility to fractional-N spurs. In a third aspect, jammer detect information is used to determine the comparison reference clock signal frequency.

Abstract: A tunable SAW resonator circuit is disclosed. The tunable SAW resonator circuit includes a SAW resonator having a Q, a resistor coupled to the SAW resonator to reduce the Q, and a tuning component coupled to the SAW resonator to tune the SAW resonator. A method to tune the SAW resonator is also disclosed. The SAW resonator may be tuned by applying a control signal to the tuning component.