Techniques are provided to more accurately determine reflected power, reflection coefficient, and/or voltage standing wave to permit prompt protection of components such as power amplifiers and notify communication system operators. This is accomplished by more accurately determining an amplitude and phase of an output reflected signal at an output port of a bidirectional coupler as a function of the following: an amplitude and a phase of a coupled forward signal coupled into a forward coupled port of the bidirectional coupler; an amplitude and a phase of a coupled reverse signal coupled into a reverse coupled port of the bidirectional coupler; an electrical transmission parameter from an input port of the bidirectional coupler to the forward coupled port; an electrical transmission parameter from the input port to the reverse coupled port; and an electrical transmission parameter from an output port of the bidirectional coupler to the reverse coupled port.

A radio calibration system includes an FPGA that generates a calibration signal by a pseudo noise generator and mixes the calibration signal with a carrier generated by a carrier generator. The FPGA injects the calibration signal into an analog electronic device which couples the calibration signal into a receiver channel. The receiver channel measures calibration signal power, group delay, and phase, and performs calibration based on these measurements. A reference clock synchronizes the pseudo noise generator, the carrier generator and the receiver channel.

A filter circuit includes a branch line coupler and a balun circuit having an input terminal connected to the branch line coupler to receive a signal, a first line connected to the input terminal and having a length comparable to a quarter of an electrical length of one wavelength at a frequency of the signal, a second line connected to the input terminal and having a length comparable to the quarter, a third line connected to the second line and having a length comparable to the quarter, and a fourth line connected to the third line and electromagnetically coupled to the first line, the fourth line having a length comparable to the quarter, wherein an end of the first line and an end of the fourth line are both connected to a ground or open-circuited, or are connected to two respective terminating resistors whose resistance values are equal.

A directional coupler includes a main line, sub-lines, and a switch. The sub-lines are located at positions that enable the sub-lines to be electromagnetically coupled to the main line. The switch is coupled between an end portion sand an end portion of the sub-line. The switch is configured to switch connection of the end portion and the end portion between a shorted state and an open state.

A directional coupler includes a main line, sub-lines, and a switch. The sub-lines are located at positions that enable the sub-lines to be electromagnetically coupled to the main line. The switch is coupled between an end portion sand an end portion of the sub-line. The switch is configured to switch connection of the end portion and the end portion between a shorted state and an open state.

Disclosed is a device including a first line, a second line including a first section disposed on a first side of the first line and a second section disposed on a second side of the first line, the second side being opposite to the first side and the second section being separate from the first section by a distance, and at least one bridge electrically connecting an end of the first section with an end of the second section and extending across the first line. The device may be a directional coupler that achieves significantly higher directivity than conventional directional coupler structures, and hence, improves power detection accuracy.

Techniques relate to an on-chip Josephson parametric converter. A Josephson ring modulator includes four nodes. A lossless on-chip flux line is capacitively coupled to two adjacent nodes of the four nodes of the Josephson ring modulator. The lossless on-chip flux line has an input port configured to receive a pump drive signal that couples differentially to the two adjacent nodes of the of the Josephson ring modulator. The pump drive signal thereby excites a common mode of the on-chip Josephson parametric converter.

A directional coupler disclosed herein may include a main line provided on a substrate, the main line having a first end connected to an input port and a second end connected to an output port. The coupler may include a coupled line disposed on the substrate, the coupled line having a first end connected to a coupled port and a second end to an isolated port. The main line is electrically isolated from the coupled line. The coupled line includes multiple turns forming a winding, and a portion of the winding overlaps with the main line. The coupled line forms a plurality of windings inductively coupled with the main line. The main line and the coupled line are routed to propagate electric signals on both lines in a same direction, and enhance inductive coupling by mutual inductance.

A coupling methodology and circuit arrangements to provide multi-frequency simultaneous power measurement. In one example, a wireless device front-end apparatus includes a plurality of antenna swap switches each connected to first and second antenna contacts, and a plurality of electromagnetic couplers each having an input port to receive a input signal of a unique frequency, a coupled port that provides a coupled signal based on the input signal, an output port connected to one of the plurality of antenna swap switches, and an isolation port. The apparatus further includes a termination network including a plurality of termination loads, and an output switch network configured to selectively connect the coupled port of each electromagnetic coupler to a coupler output bank to provide the coupled signals at the coupler output bank, and to selectively connect the isolation port of each electromagnetic coupler to one of the plurality of termination loads.

A coupling methodology and circuit arrangements to provide multi-frequency simultaneous power measurement. In one example, a wireless device front-end apparatus includes a plurality of antenna swap switches each connected to first and second antenna contacts, and a plurality of electromagnetic couplers each having an input port to receive a input signal of a unique frequency, a coupled port that provides a coupled signal based on the input signal, an output port connected to one of the plurality of antenna swap switches, and an isolation port. The apparatus further includes a termination network including a plurality of termination loads, and an output switch network configured to selectively connect the coupled port of each electromagnetic coupler to a coupler output bank to provide the coupled signals at the coupler output bank, and to selectively connect the isolation port of each electromagnetic coupler to one of the plurality of termination loads.