Abstract: A device combines filter circuits to be connected to an antenna, enabling carrier aggregation for wireless communications over multiple RF frequency bands in different operational environments. The device includes first, second and third filter circuits having first, second and third matching networks and one or more first, second and third band pass filters with corresponding passbands, respectively. The device further includes multiple individual matching networks not dedicated to any of the first, second or third filter circuits, and a multi-state switch configured to provide different filter circuit combinations by selectively connecting at least two of the first, second and third filter circuits, respectively, and at least one individual matching network of the multiple matching networks. Each filter circuit combination includes a combined matching network having at least two of the first, second and third matching networks and the at least one individual matching network.

Abstract: A device combines filter circuits to be connected to an antenna, enabling carrier aggregation for wireless communications over multiple RF frequency bands in different operational environments. The device includes first, second and third filter circuits having first, second and third matching networks and one or more first, second and third band pass filters with corresponding passbands, respectively. The device further includes multiple individual matching networks not dedicated to any of the first, second or third filter circuits, and a multi-state switch configured to provide different filter circuit combinations by selectively connecting at least two of the first, second and third filter circuits, respectively, and at least one individual matching network of the multiple matching networks. Each filter circuit combination includes a combined matching network having at least two of the first, second and third matching networks and the at least one individual matching network.

Abstract: LC tank and ring-based VCOs are disclosed that each include a differential pair of transistors for steering a tail current generated by a current source responsive to a bias voltage. A biasing circuit generates the bias voltage such that a transconductance for the transistors in the differential pairs is inversely proportional to a resistance.

Abstract: In one embodiment, a voltage-controlled oscillator (VCO) is provided having an output signal having a frequency responsive to a tuning signal. The VCO includes: a plurality of inverters coupled to form a loop, each differential inverter having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a bias voltage, each inverter stage including a plurality of switched-capacitor circuits configured to control a signal delay through the inverter stage response to the tuning signal so as to control the frequency of the output signal; and a bias circuit configured to generate the bias voltage responsive to a reference signal such that an amplitude of the output signal is substantially independent of the output signal frequency and depends upon the reference signal.

Abstract: In one embodiment, a voltage-controlled oscillator (VCO) is provided that includes: a plurality of differential inverters coupled to form a loop, each differential inverter having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a bias voltage, wherein each transistor in the differential pair couples to a power source through a corresponding switching-capacitor circuit; and a bias circuit configured to generate the bias voltage such that a transconductance for each transistor in the differential pairs is proportional to a factor that is a function of a ratio of transistor widths within the bias circuit.

Abstract: LC tank and ring-based VCOs are disclosed that each include a differential pair of transistors for steering a tail current generated by a current source responsive to a bias voltage. A biasing circuit generates the bias voltage such that a transconductance for the transistors in the differential pairs is inversely proportional to a resistance.

Abstract: In one embodiment, a voltage-controlled oscillator (VCO) is provided having an output signal having a frequency responsive to a tuning signal. The VCO includes: a plurality of inverters coupled to form a loop, each differential inverter having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a bias voltage, each inverter stage including a plurality of switched-capacitor circuits configured to control a signal delay through the inverter stage response to the tuning signal so as to control the frequency of the output signal; and a bias circuit configured to generate the bias voltage responsive to a reference signal such that an amplitude of the output signal is substantially independent of the output signal frequency and depends upon the reference signal.

Abstract: In one embodiment, a voltage-controlled oscillator (VCO) is provided that includes: a plurality of differential inverters coupled to form a loop, each differential inverter having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a bias voltage, wherein each transistor in the differential pair couples to a power source through a corresponding switching-capacitor circuit; and a bias circuit configured to generate the bias voltage such that a transconductance for each transistor in the differential pairs is proportional to a factor that is a function of a ratio of transistor widths within the bias circuit.

Abstract: A transconductance-capacitance (Gm-C) filter of arbitrary order is provided that is biased by a bias circuit such that the Gm-C filter is robust to variations in process corner and temperature as well as input supply noise. The bias circuit includes a biased transistor that has a width-to-length ratio that is a factor X times larger than a corresponding transistor in the Gm-C filter. The biased transistor couples to ground through a switched capacitor circuit.

Abstract: A transconductance-capacitance (Gm-C) filter of arbitrary order is provided that is biased by a bias circuit such that the Gm-C filter is robust to variations in process corner and temperature as well as input supply noise. The bias circuit includes a biased transistor that has a width-to-length ratio that is a factor X times larger than a corresponding transistor in the Gm-C filter. The biased transistor couples to ground through a switched capacitor circuit.

Abstract: A pulse generator is provided that includes: a current source, a source follower whose output controls the gate of a FET and a differential stage whose input voltage consists of inverting square waves and its output voltage consists of extremely narrow pulses widths, for example, of 30 to 40 ps and amplitude of 1.5 Volts.

Abstract: In one embodiment, a switching power amplifier is provided that includes: a power switch coupled between a power supply node and ground, wherein the power switch is configured to be cycled on and off responsive to an input signal voltage; and a matching network coupled between a terminal of the power switch and an output node, wherein the matching network includes: a first capacitor coupled between the terminal of the power switch and ground; a second capacitor having a first terminal and an opposing second terminal, the second terminal being coupled to ground, the second capacitor having a greater capacitance than the first capacitor; and a second switch coupled between the first terminal of the second capacitor and the terminal of the power switch, the second switch being configured to be cycled on and off responsive to a switching signal voltage such that the second switch is turned on before the power switch is turned off and such that the second switch is turned off after a current through the power swit

Abstract: In one embodiment, a voltage-controlled oscillator (VCO) is provided that includes: a plurality of differential inverter stages coupled to form a loop, each differential inverter stage having including a switched capacitor circuit configured to control a signal delay through the differential inverter stage responsive to a control circuit, whereby an output frequency for the VCO is inherently compensated against changes in semiconductor process variations and thermal variations.

Abstract: In one embodiment, a voltage-controlled oscillator is provided having an output signal whose frequency is responsive to a tuning signal and is independent of amplitude of oscillation. The voltage-controlled oscillator includes: a plurality of differential inverter stages coupled to form a loop, each differential inverter stage having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a feedback signal; and a control circuit configured to generate the feedback signal responsive to a reference signal such that an amplitude of the output signal is independent of the tuning signal and depends on the reference signal, and the frequency of oscillation is decoupled from the amplitude of oscillation.

Abstract: In one embodiment, a switching power amplifier is provided that includes: a power switch coupled between a power supply node and ground, wherein the power switch is configured to be cycled on and off responsive to an input signal voltage; and a matching network coupled between a terminal of the power switch and an output node, wherein the matching network includes: a first capacitor coupled between the terminal of the power switch and ground; a second capacitor having a first terminal and an opposing second terminal, the second terminal being coupled to ground, the second capacitor having a greater capacitance than the first capacitor; and a second switch coupled between the first terminal of the second capacitor and the terminal of the power switch, the second switch being configured to be cycled on and off responsive to a switching signal voltage such that the second switch is turned on before the power switch is turned off and such that the second switch is turned off after a current through the power swit

Abstract: A pulse generator is provided that includes: a current source, a source follower whose output controls the gate of a FET and a differential stage whose input voltage consists of inverting square waves and its output voltage consists of extremely narrow pulses widths, for example, of 30 to 40 ps and amplitude of 1.5 Volts.

Abstract: In one embodiment, a voltage-controlled oscillator (VCO) is provided that includes: a plurality of differential inverter stages coupled to form a loop, each differential inverter stage having including a switched capacitor circuit configured to control a signal delay through the differential inverter stage responsive to a control circuit, whereby an output frequency for the VCO is inherently compensated against changes in semiconductor process variations and thermal variations.

Abstract: In one embodiment, a voltage-controlled oscillator is provided having an output signal whose frequency is responsive to a tuning signal and is independent of amplitude of oscillation. The voltage-controlled oscillator includes: a plurality of differential inverter stages coupled to form a loop, each differential inverter stage having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a feedback signal; and a control circuit configured to generate the feedback signal responsive to a reference signal such that an amplitude of the output signal is independent of the tuning signal and depends on the reference signal, and the frequency of oscillation is decoupled from the amplitude of oscillation.