Abstract: A system for managing a reference clock signal includes an XO; a signal buffer coupled to the XO and configured to drive a reference clock signal generated by the XO; and a first IC coupled to the signal buffer. The first IC includes an XO input buffer configured to receive the reference clock signal, to switch between an enabled, operational state and a disabled state, and to have a first operational impedance while in the enabled state; an impedance equivalence circuit configured to be in an enabled, operational state when the XO input buffer is in its disabled state and vice versa and to have a second operational impedance while in the enabled state that is equivalent to the first operational impedance; and a control mechanism configured to switch the XO input buffer and the impedance equivalence circuit between the enabled state and the disabled state.

Abstract: A wireless device includes: an antenna; and a polar-modulation transmitter coupled to the antenna and configured for two-point modulation, the transmitter including: a data input; a first signal path including a multiplier coupled to the data input and a voltage-controlled oscillator gain adaptation module coupled to the multiplier and configured to provide a gain value to the multiplier; and a second signal path coupled to the data input and including an analog phase-locked loop (PLL) including a voltage-controlled oscillator (VCO) coupled to the first signal path.

Abstract: A tunable oscillator circuit is disclosed. The tunable oscillator circuit includes an inductor/capacitor (LC) tank circuit comprising a primary inductor coupled in parallel with a first capacitor bank. The LC tank resonates to produce an oscillating voltage at a frequency. The tunable oscillator circuit also includes a 90 degree phase shift buffer coupled to the LC tank and a transconductor. The transconductor is coupled to the 90 degree phase shift buffer and a secondary inductor. The tunable oscillator circuit also includes a secondary inductor that is inductively coupled to the primary inductor and receives a gain-scaled oscillating current from the transconductor. By changing the transconductance, the gain-scaled oscillating current in the secondary inductor will change, thus the effective primary inductance and the oscillation frequency can be tuned.

Abstract: A system for managing a reference clock signal includes an XO; a signal buffer coupled to the XO and configured to drive a reference clock signal generated by the XO; and a first IC coupled to the signal buffer. The first IC includes an XO input buffer configured to receive the reference clock signal, to switch between an enabled, operational state and a disabled state, and to have a first operational impedance while in the enabled state; an impedance equivalence circuit configured to be in an enabled, operational state when the XO input buffer is in its disabled state and vice versa and to have a second operational impedance while in the enabled state that is equivalent to the first operational impedance; and a control mechanism configured to switch the XO input buffer and the impedance equivalence circuit between the enabled state and the disabled state.

Abstract: A method includes generating a first signal based on a difference between a first frequency of a first voltage controlled oscillator (VCO) and a second frequency of a second VCO. The method further includes determining a gain of the first VCO at least partially based on the first signal.

Abstract: A wafer test probe for testing integrated circuitry on a die is disclosed. The wafer test probe includes a membrane core. The wafer test probe also includes circuitry within the membrane core. The circuitry within the membrane core includes at least one portion of an inductor. The wafer test probe further includes a probe tip.

Abstract: Multi-mode oscillators supporting multiple modes and having different desirable characteristics (e.g., good phase noise or low power consumption) in different modes are disclosed. In an exemplary design, an apparatus includes first and second transistors of a first transistor type (e.g., NMOS transistors) and third and fourth transistors of a second transistor type (e.g., PMOS transistors) for a multi-mode oscillator. The third and fourth transistors are coupled (e.g., directly) to the first and second transistors. The first and second transistors are enabled in a first mode to provide signal gain for the oscillator and generate an oscillator signal in the first mode. The first to fourth transistors are enabled in a second mode to provide signal gain for the oscillator and generate the oscillator signal in the second mode. Different supply voltages may be provided at different supply nodes of the oscillator in the first and second modes.

Abstract: A method for reducing spurs within a transmit signal is disclosed. A cancelling tone is determined. The cancelling tone is added to a baseband transmit signal in the digital domain to obtain a baseband transmit signal with cancelling tone. A spur in the transmit signal is reduced using the cancelling tone. The transmit signal with the reduced spur is transmitted using an antenna.

Abstract: A VCO includes a transformer-based resonator that has a first LC tank and a second LC tank. The resonator has an even resonant mode and an odd resonant mode. The VCO further includes an active transconductance network that is coupled to a two-terminal port of the first tank and is also coupled to a two-terminal port of the second tank. A first terminal of the port of the first tank is capacitively coupled to a first terminal of the port of the second tank. A second terminal of the port of the first tank is capacitively coupled to a second terminal of the port of the second tank. The active transconductance network causes the resonator to resonate in a selectable one of the even and odd resonant modes depending on a digital control signal. The VCO is fine tuned by changing the capacitances of capacitors of the tanks.

Abstract: A tunable oscillator circuit is disclosed. The tunable oscillator circuit includes an inductor/capacitor (LC) tank circuit comprising a primary inductor coupled in parallel with a first capacitor bank. The LC tank resonates to produce an oscillating voltage at a frequency. The tunable oscillator circuit also includes a 90 degree phase shift buffer coupled to the LC tank and a transconductor. The transconductor is coupled to the 90 degree phase shift buffer and a secondary inductor. The tunable oscillator circuit also includes a secondary inductor that is inductively coupled to the primary inductor and receives a gain-scaled oscillating current from the transconductor. By changing the transconductance, the gain-scaled oscillating current in the secondary inductor will change, thus the effective primary inductance and the oscillation frequency can be tuned.

Abstract: An assembly involves an integrated circuit die that is bonded, e.g., flip-chip bonded, to a non-semiconductor substrate by a plurality of low-resistance microbumps. In one novel aspect, at least a part of a novel high-frequency transformer is disposed in the non-semiconductor substrate where the non-semiconductor substrate is the substrate of a ball grid array (BGA) integrated circuit package. At least one of the low-resistance microbumps connects the part of the transformer in the substrate to a circuit in the integrated circuit die. At two gigahertz, the novel transformer has a coupling coefficient k of at least at least 0.4 and also has a transformer quality factor Q of at least ten. The novel transformer structure sees use in coupling differential outputs of a mixer to a single-ended input of a driver amplifier in a transmit chain of an RF transceiver within a cellular telephone.

Abstract: A VCO includes a transformer-based resonator that has a first LC tank and a second LC tank. The resonator has an even resonant mode and an odd resonant mode. The VCO further includes an active transconductance network that is coupled to a two-terminal port of the first tank and is also coupled to a two-terminal port of the second tank. A first terminal of the port of the first tank is capacitively coupled to a first terminal of the port of the second tank. A second terminal of the port of the first tank is capacitively coupled to a second terminal of the port of the second tank. The active transconductance network causes the resonator to resonate in a selectable one of the even and odd resonant modes depending on a digital control signal. The VCO is fine tuned by changing the capacitances of capacitors of the tanks.

Abstract: An apparatus for implementing phase rotation at baseband frequency for transmit diversity may include a primary transmit signal path and a diversity transmit signal path. Both the primary transmit signal path and the diversity transmit signal path may receive a primary transmit signal. A signal selector within the diversity transmit signal path may perform phase rotation with respect to the primary transmit signal while the primary transmit signal is at a baseband frequency, thereby producing a diversity transmit signal.

Abstract: A wafer test probe for testing integrated circuitry on a die is disclosed. The wafer test probe includes a membrane core. The wafer test probe also includes circuitry within the membrane core. The circuitry within the membrane core includes at least one portion of an inductor. The wafer test probe further includes a probe tip.

Abstract: A method for reducing spurs within a transmit signal is disclosed. A cancelling tone is determined. The cancelling tone is added to a baseband transmit signal in the digital domain to obtain a baseband transmit signal with cancelling tone. A spur in the transmit signal is reduced using the cancelling tone. The transmit signal with the reduced spur is transmitted using an antenna.

Abstract: An assembly involves an integrated circuit die that is bonded, e.g., flip-chip bonded, to a non-semiconductor substrate by a plurality of low-resistance microbumps. In one novel aspect, at least a part of a novel high-frequency transformer is disposed in the non-semiconductor substrate where the non-semiconductor substrate is the substrate of a ball grid array (BGA) integrated circuit package. At least one of the low-resistance microbumps connects the part of the transformer in the substrate to a circuit in the integrated circuit die. At two gigahertz, the novel transformer has a coupling coefficient k of at least at least 0.4 and also has a transformer quality factor Q of at least ten. The novel transformer structure sees use in coupling differential outputs of a mixer to a single-ended input of a driver amplifier in a transmit chain of an RF transceiver within a cellular telephone.

Abstract: An apparatus for implementing phase rotation at baseband frequency for transmit diversity may include a primary transmit signal path and a diversity transmit signal path. Both the primary transmit signal path and the diversity transmit signal path may receive a primary transmit signal. A signal selector within the diversity transmit signal path may perform phase rotation with respect to the primary transmit signal while the primary transmit signal is at a baseband frequency, thereby producing a diversity transmit signal.

Abstract: A programmable varactor apparatus may include multiple binary weighted varactors controlled by multiple digital varactor bits. A programmable varactor apparatus may include a plurality of binary weighted varactors, and a control to selectively disable one or more of the plurality of binary weighted varactors to decrease an effective capacitance of the programmable varactor apparatus. A method for changing an effective capacitance of a programmable varactor apparatus may include providing a plurality of binary weighted varactors, and disabling one or more of the plurality of binary weighted varactors to decrease the effective capacitance of the programmable varactor apparatus.

Abstract: A programmable varactor apparatus may include multiple binary weighted varactors controlled by multiple digital varactor bits. A programmable varactor apparatus may include a plurality of binary weighted varactors, and a control to selectively disable one or more of the plurality of binary weighted varactors to decrease an effective capacitance of the programmable varactor apparatus. A method for changing an effective capacitance of a programmable varactor apparatus may include providing a plurality of binary weighted varactors, and disabling one or more of the plurality of binary weighted varactors to decrease the effective capacitance of the programmable varactor apparatus.