A bi-directional coupler includes a first individual directional coupler and a second individual directional coupler, which are individual electronic components having mutually equivalent circuit configurations. Each of the first and second individual directional couplers includes: a first terminal; a second terminal; a third terminal; a fourth terminal; a main line connecting the first terminal and the second terminal; and a subline connecting the third terminal and the fourth terminal. The subline includes first and second coupling line sections configured to be electromagnetically coupled to the main line, and a matching section provided between the first and second coupling line sections. The second terminal of the second individual directional coupler is electrically connected to the second terminal of the first individual directional coupler.

A bi-directional coupler includes a first individual directional coupler and a second individual directional coupler, which are individual electronic components having mutually equivalent circuit configurations. Each of the first and second individual directional couplers includes: a first terminal; a second terminal; a third terminal; a fourth terminal; a main line connecting the first terminal and the second terminal; and a subline connecting the third terminal and the fourth terminal. The subline includes first and second coupling line sections configured to be electromagnetically coupled to the main line, and a matching section provided between the first and second coupling line sections. The second terminal of the second individual directional coupler is electrically connected to the second terminal of the first individual directional coupler.

In one example, a signal processing circuit including a directional coupler and a termination part is disclosed. The directional coupler includes a main line as a transmission path of an RF signal and a sub-line constituting a coupled line together with the main line. The termination part includes devices connectable between ground and a first port at an end of the sub-line. The signal processing circuit switches, depending on a frequency of the RF signal, the devices of the termination part to be connected to the first port. The phase of a return signal of a signal input as a coupling signal to the termination part via the first port is opposite to the phase of an isolation signal supplied to a second port at the other end of the sub-line and connected to an output port of the coupling signal.

In one example, a signal processing circuit including a directional coupler and a termination part is disclosed. The directional coupler includes a main line as a transmission path of an RF signal and a sub-line constituting a coupled line together with the main line. The termination part includes devices connectable between ground and a first port at an end of the sub-line. The signal processing circuit switches, depending on a frequency of the RF signal, the devices of the termination part to be connected to the first port. The phase of a return signal of a signal input as a coupling signal to the termination part via the first port is opposite to the phase of an isolation signal supplied to a second port at the other end of the sub-line and connected to an output port of the coupling signal.

A bidirectional coupler includes a first main line that transmits a first signal from a first input end thereof to a first output end thereof, a second main line that transmits a second signal from a second input end thereof to a second output end thereof, a first sub-line having a first end corresponding to the first input end and a second end corresponding to the first output end, a second sub-line having a first end corresponding to the second input end and a second end corresponding to the second output end, a detector port, a termination circuit, and a switch circuit. The first end of the first sub-line and the first end of the second sub-line are connected to each other.

A bidirectional coupler includes a first main line that transmits a first signal from a first input end thereof to a first output end thereof, a second main line that transmits a second signal from a second input end thereof to a second output end thereof, a first sub-line having a first end corresponding to the first input end and a second end corresponding to the first output end, a second sub-line having a first end corresponding to the second input end and a second end corresponding to the second output end, a detector port, a termination circuit, and a switch circuit. The first end of the first sub-line and the first end of the second sub-line are connected to each other.

Methods and devices to address antenna termination in absence of power supplies within an electronic circuit including a termination circuit and a switching circuit. The devices include regular NMOS devices that decouple the antenna from the switching circuit in absence of power supplies while the antenna is coupled to a terminating impedance having a desired impedance value through a native NMOS device. The antenna is coupled with the switching circuit via the regular NMOS device during powered conditions while the antenna is decoupled from the terminating impedance.

Methods and devices to address antenna termination in absence of power supplies within an electronic circuit including a termination circuit and a switching circuit. The devices include regular NMOS devices that decouple the antenna from the switching circuit in absence of power supplies while the antenna is coupled to a terminating impedance having a desired impedance value through a native NMOS device. The antenna is coupled with the switching circuit via the regular NMOS device during powered conditions while the antenna is decoupled from the terminating impedance.

A waveguide circuit (1) includes a first waveguide tube (10), a second waveguide tube (20), and a third waveguide tube (30). The first waveguide tube (10), the second waveguide tube (20), and the third waveguide tube (30) have cross-sectional shapes to allow propagation of TE modes. The tube axis of the second waveguide tube (20) is parallel to the tube axis of the first waveguide tube (10). One of the narrow sidewalls of the second waveguide tube (20) faces a narrow sidewall (10s) of the first waveguide tube (10). The third waveguide tube (30) includes a coupler that connects a hollow guide of the third waveguide tube (30) to a hollow guide of the first waveguide tube (10) and a hollow guide of the second waveguide tube (20).

A waveguide circuit (1) includes a first waveguide tube (10), a second waveguide tube (20), and a third waveguide tube (30). The first waveguide tube (10), the second waveguide tube (20), and the third waveguide tube (30) have cross-sectional shapes to allow propagation of TE modes. The tube axis of the second waveguide tube (20) is parallel to the tube axis of the first waveguide tube (10). One of the narrow sidewalls of the second waveguide tube (20) faces a narrow sidewall (10s) of the first waveguide tube (10). The third waveguide tube (30) includes a coupler that connects a hollow guide of the third waveguide tube (30) to a hollow guide of the first waveguide tube (10) and a hollow guide of the second waveguide tube (20).