A digital phase shifter is described where each bit of the phase shifter has a circuit block including one PIN diode in parallel with one transmission line. The phase shifter requires only one PIN diode and one transmission line per bit circuit block. Each PIN diode behaves like a simple switch for phase shifting. When the PIN diode is forward biased (on state), current flows through the PIN diode and the RF signal is not phase shifted. When the pin diode is not forward biased (off state), current flows through the transmission line parallel to the PIN diode and the RF signal is phase shifted by the transmission line. The digital phase shifter may have n circuit blocks in series, and adjacent PIN diodes may share a current when both are on. The phase shifter may be implemented in a phased array or reflect array antenna including multiple phase shifters.

A variable attenuator operable in a frequency band from at least 10 GHz is disclosed. The variable attenuator includes an input port; an output port; a first transmission line connecting the input port with the output port; an attenuating unit provided between the first transmission line and the ground; and a second transmission line. The attenuating unit includes at least one transistor with two current terminals coupled with the first transmission line and ground, respectively. The second transmission line is coupled between the two current terminals of the transistor. The second transmission line is operable as an inductor in the frequency band. A feature of the variable attenuator is that the transistor and the second transmission line cause a resonance frequency within the frequency band by a capacitor between the two current terminals and the inductance of the second transmission line.

A phase-shifting circuit 1 includes a signal conductor 2 that transmits signals, and a dielectric body 3 that is disposed to overlap the signal conductor 2, said phase-shifting circuit changing the phase of the signals by changing the area of an overlapping section 5 where the signal conductor 2 and the dielectric body 3 overlap each other. The phase-shifting circuit further includes a transformer unit 7 for matching impedance between the overlapping section 5 and non-overlapping section 6 where the signal conductor 2 and the dielectric body 3 do not overlap each other, said transformer unit being provided at end sections of the dielectric body 3, said end sections being on the input side and output side of the signals. The transformer unit 7 includes a high-impedance section 7a that is provided on the overlapping section 5 side, and a low-impedance section 7b, which is provided on the non-overlapping section 6 side of the high-impedance section 7a, and which has a lower characteristic impedance than the high-impedance section 7a.

According to various embodiments, a quadrature hybrid coupler included as part of a phase shifter is used to provide variable phase shift to an input signal. The quadrature hybrid coupler includes an input port, an output port, and two terminated ports. The phase shifter includes one or more static lumped elements connected to the QHC to reduce at least one electrical dimension of the QHC to substantially less than a quarter wavelength. The phase shifter also include one or more variable lumped elements connected to the QHC to provide a variable phase shift to the input signal between the input port and the output port of the QHC.

A transmission-line-based impedance transformer including first and second couplers, with each coupler including respective pairs of coupled signal conductors. The signal conductors are connected sequentially in series between an input port and an output port and may form a single spiral configuration. A signal conductor of one coupler may be connected in series between the two signal conductors of another coupler. The couplers have characteristic impedances between an input impedance and an output impedance. A signal conductor of a coupler may include first and second conductor portions disposed in respective spaced-apart parallel planes, with the other signal conductor of the coupler disposed physically directly between the conductor portions. A signal conductor in the spiral may be shielded from coupled signal conductors by ground conductors disposed in respective spaced-apart parallel planes on opposite sides of the shielded signal conductor. The first and second couplers may have a shared signal conductor.

A passive phase shifter includes a reference line and a half-wavelength transmission line, where the half-wavelength transmission line is loaded with a perpendicular quarter wavelength rectangular stub and a quarter wavelength radial stub structure connected in series.

A control circuit (16) is configured to detect the impedance P1 of a load (3) and control each of the reactance value L1 of a first variable reactance element (12), the reactance value L2 of a second variable reactance element (14), and the phase shift amount of a phase shifter (15) on the basis of the detected impedance P1. Consequently, impedance matching can be achieved even with the phase shifter (15) that performs discrete phase shift control.

A method for in-phase (I) and quadrature (Q) signal generation is disclosed. The method may include a first stage receiving a differential input signal. The first stage may also generate first differential in-phase and quadrature output signals, which may be sent by the first stage to a second stage. The second stage may generate second differential in-phase and quadrature output signals, which may have amplitude and phase mismatches less than an amplitude and phase mismatches of the first differential output signals. The second stage may then output the second differential I/Q output signals.

A transmission-line-based impedance transformer including first and second couplers, with each coupler including respective pairs of coupled signal conductors. The signal conductors are connected sequentially in series between an input port and an output port and may form a single spiral configuration. A signal conductor of one coupler may be connected in series between the two signal conductors of another coupler. The couplers have characteristic impedances between an input impedance and an output impedance. A signal conductor of a coupler may include first and second conductor portions disposed in respective spaced-apart parallel planes, with the other signal conductor of the coupler disposed physically directly between the first and second conductor portions. A transmission-line signal conductor in the spiral may be shielded from coupled signal conductors by ground conductors disposed in respective spaced-apart parallel planes on opposite sides of the shielded signal conductor.

A passive vector modulator (PVM) includes a divider that splits an input signal into a first divided signal and a second divided signal 90 apart in phase. The PVM includes a switched transformer phase shifter including primary windings to form first primary windings and second primary windings receiving the first divided signal and the second divided signal respectively. First secondary windings are coupled to the first primary windings, the first secondary windings being center-tapped and outputting first and second phase shifted output signals, phase shifted 180 and 0 respectively. Second secondary windings are coupled to the second primary windings, the second secondary windings being center-tapped and outputting third and fourth phase shifted signals, phase shifted 270 and 90 respectively. The PVM includes a switch configured to receive the phase shifted output signals. The switch selectively outputs one of the phase shifted output signals, or a combination, from the PVM.