A resistor calibration system includes a reference resistor, a first control circuit, a second control circuit, a comparator, a multiplexer and a de-multiplexer. The first control circuit calibrates a first resistor and a duplicated first resistor. The second control circuit calibrates a second resistor. The comparator includes a first input terminal receiving a reference voltage, a second input terminal and an output terminal. The multiplexer includes a first input terminal coupled to the reference resistor and the first resistor, a second input terminal coupled to the duplicated first resistor and the second resistor, and an output terminal coupled to the second input terminal of the comparator. The de-multiplexer includes an input terminal coupled to the output terminal of the comparator, a first output terminal coupled to the first control circuit, and a second output terminal coupled to the second control circuit.

A configurable RF transmit/receive (TX/RX) multiplexer, which includes a group of RF TX bandpass filters, a group of RF TX switching elements, and a group of RF RX bandpass filters; is disclosed. Each of the group of RF RX bandpass filters is coupled to a first common connection node. Each of the group of RF TX switching elements is coupled between a corresponding one of the group of RF TX bandpass filters and the first common connection node, which is coupled to a first RF antenna.

A system that incorporates teachings of the present disclosure may include, for example, an adaptive impedance matching network having an RF matching network coupled to at least one RF input port and at least one RF output port and comprising one or more controllable variable reactive elements. The RF matching network can be adapted to reduce a level of reflected power transferred from said at least one input port by varying signals applied to said controllable variable reactive elements. The one or more controllable variable reactive elements can be coupled to a circuit adapted to map one or more control signals that are output from a controller to a signal range that is compatible with said one or more controllable variable reactive elements. Additional embodiments are disclosed.

A system that incorporates teachings of the present disclosure may include, for example, an adaptive impedance matching network having an RF matching network coupled to at least one RF input port and at least one RF output port and comprising one or more controllable variable reactive elements. The RF matching network can be adapted to reduce a level of reflected power transferred from said at least one input port by varying signals applied to said controllable variable reactive elements. The one or more controllable variable reactive elements can be coupled to a circuit adapted to map one or more control signals that are output from a controller to a signal range that is compatible with said one or more controllable variable reactive elements. Additional embodiments are disclosed.

An impedance matching device includes: a variable capacitor in which a plurality of series circuits of capacitors and semiconductor switches are connected in parallel; a calculation unit that calculates an impedance or a reflection coefficient on the load side using information regarding impedance acquired from the outside; and a control unit that determines ON/OFF states to be taken by the semiconductor switches included in the variable capacitor using the impedance or the reflection coefficient calculated by the calculation unit and turns on or off the semiconductor switches based on the determined states. The control unit changes an ON/OFF control timing between one and another of the semiconductor switches.

An impedance matching device includes: a variable capacitor in which a plurality of series circuits of capacitors and semiconductor switches are connected in parallel; a calculation unit that calculates an impedance or a reflection coefficient on the load side using information regarding impedance acquired from the outside; and a control unit that determines ON/OFF states to be taken by the semiconductor switches included in the variable capacitor using the impedance or the reflection coefficient calculated by the calculation unit and turns on or off the semiconductor switches based on the determined states. The control unit changes an ON/OFF control timing between one and another of the semiconductor switches.

A drive circuit performs switching between an on-state and an off-state of a PIN diode, the drive circuit being provided with a switching element and a switching element, a drive power supply, and a current limiting resistor that adjusts a forward current of the PIN diode. When the switching element is in an on-state and the switching element is in an off-state, the PIN diode is switched to the on-state by applying a forward voltage to the PIN diode from the drive power supply via the current limiting resistor, and when the switching element is in the off-state and the switching element is in the on-state, the PIN diode is switched to the off-state by applying, not via the current limiting resistor, a reverse voltage to the PIN diode from the drive power supply.

A drive circuit performs switching between an on-state and an off-state of a PIN diode, the drive circuit being provided with a switching element and a switching element, a drive power supply, and a current limiting resistor that adjusts a forward current of the PIN diode. When the switching element is in an on-state and the switching element is in an off-state, the PIN diode is switched to the on-state by applying a forward voltage to the PIN diode from the drive power supply via the current limiting resistor, and when the switching element is in the off-state and the switching element is in the on-state, the PIN diode is switched to the off-state by applying, not via the current limiting resistor, a reverse voltage to the PIN diode from the drive power supply.

An amplifier circuit for a millimeter wave (mmW) communication system includes an amplifier coupled to a matching network, and a variable gain control circuit in the matching network, the variable gain control circuit having an adjustable gain control resistance, the adjustable gain control resistance having adjustable segments and a center node therebetween, the center node coupled to an alternating current (AC) ground.

An amplifier circuit for a millimeter wave (mmW) communication system includes an amplifier coupled to a matching network, and a variable gain control circuit in the matching network, the variable gain control circuit having an adjustable gain control resistance, the adjustable gain control resistance having adjustable segments and a center node therebetween, the center node coupled to an alternating current (AC) ground.