A directional coupler circuit includes a signal line disposed between a first terminal and a second terminal; a coupling line comprising a first end terminal and a second end terminal, and disposed to be coupled to the signal line; a switching circuit connecting the first end terminal and a coupling port to each other to extract a first coupling signal in a first coupling mode, and connecting the second end terminal and the coupling port to extract a second coupling signal in a second coupling mode; and a phase compensating circuit configured to compensate for a phase difference between the coupling port and a first isolation port in the first coupling mode, or compensate for a phase difference between the coupling port and a second isolation port in the second coupling mode.

A multiport microwave device includes a first reactive three-port microwave device, a second reactive three-port microwave device, a third reactive three-port microwave device, and a matched four-port microwave device. The four-port microwave device includes first and second input ports and first and second output ports communicatively coupled to one another. A first port of each of the first, second and third three-port microwave devices is operative to receive a microwave signal, and a first output port and a second output port of the four-port microwave device are each operative to output a microwave signal. A second port of the first microwave device is communicatively coupled to a second port of the second microwave device, a second port of the third microwave device is communicatively coupled to a third port of the second microwave device, and a third port of the first microwave device is communicatively coupled to the first input port the four-port microwave device. A third port of the third microwave device is communicatively coupled to the second input port of the four-port microwave device.

A multiport microwave device includes a first reactive three-port microwave device, a second reactive three-port microwave device, a third reactive three-port microwave device, and a matched four-port microwave device. The four-port microwave device includes first and second input ports and first and second output ports communicatively coupled to one another. A first port of each of the first, second and third three-port microwave devices is operative to receive a microwave signal, and a first output port and a second output port of the four-port microwave device are each operative to output a microwave signal. A second port of the first microwave device is communicatively coupled to a second port of the second microwave device, a second port of the third microwave device is communicatively coupled to a third port of the second microwave device, and a third port of the first microwave device is communicatively coupled to the first input port the four-port microwave device. A third port of the third microwave device is communicatively coupled to the second input port of the four-port microwave device.

An apparatus is disclosed for an asymmetrical quadrature hybrid coupler. In an example aspect, an apparatus comprises a quadrature hybrid coupler. The quadrature hybrid coupler comprises a shared port, a through port, a coupled port, and an isolated port. The quadrature hybrid coupler also comprises at least one transformer, which comprises a first inductor and a second inductor. The first inductor is connected between the shared port and the coupled port. The second inductor is connected between the isolated port and the through port. The second inductor is directly connected to the isolated port. An inductance of the first inductor is different from an inductance of the second inductor.

A phase shifter module includes a base material, a common terminal, and individual terminals, the common terminal and the individual terminals being provided at the base material. Inside the base material, phase shifters that are connected between the individual terminals and the common terminal, respectively, are provided. The phase shifters each include a primary coil and a secondary coil that is coupled to the primary coil by magnetic field coupling and define a transformer phase shifter. With this configuration, a phase shifter module for use with SAW filters while reducing or preventing interference among the SAW filters, a multiplexer/demultiplexer that includes the phase shifter module, and a communication apparatus that includes the phase shifter module, are obtained.

A phase shifter module includes a base material, a common terminal, and individual terminals, the common terminal and the individual terminals being provided at the base material. Inside the base material, phase shifters that are connected between the individual terminals and the common terminal, respectively, are provided. The phase shifters each include a primary coil and a secondary coil that is coupled to the primary coil by magnetic field coupling and define a transformer phase shifter. With this configuration, a phase shifter module for use with SAW filters while reducing or preventing interference among the SAW filters, a multiplexer/demultiplexer that includes the phase shifter module, and a communication apparatus that includes the phase shifter module, are obtained.

A polyphase filter operates to provide capacitive compensation to drive a multiphase network for generating quadrature signals. The polyphase filter can include a capacitive compensation mechanism at internal nodes. The capacitive compensation mechanism includes a first phase lag circuit between a first internal node and a second internal node and a second phase lag circuit coupled between a third internal node and a fourth internal node. The first internal node is coupled to the second internal node via a first inductor coupled to a first resistor, the second internal node is coupled to the third internal node via a second inductor coupled to a second resistor, the third internal node is coupled to the fourth internal node via a third inductor coupled to a third resistor, and the fourth internal node is coupled to the first internal node via a fourth inductor coupled to a fourth resistor.

A polyphase filter operates to provide capacitive compensation to drive a multiphase network for generating quadrature signals. The polyphase filter can include a capacitive compensation mechanism at internal nodes. The capacitive compensation mechanism includes a first phase lag circuit between a first internal node and a second internal node and a second phase lag circuit coupled between a third internal node and a fourth internal node. The first internal node is coupled to the second internal node via a first inductor coupled to a first resistor, the second internal node is coupled to the third internal node via a second inductor coupled to a second resistor, the third internal node is coupled to the fourth internal node via a third inductor coupled to a third resistor, and the fourth internal node is coupled to the first internal node via a fourth inductor coupled to a fourth resistor.

A deployable active radar countermeasure or smart chaff device includes a flexible battery or length of reflective material for passive reflection of a surveillance radar signal. Metallized antenna elements printed onto the material receive the surveillance radar signals, and RF integrated circuitry bonded to the material generates active RF echo signals based on the frequency of the surveillance signal and the length of the material. Wirebond receiving paths include reconfigurable gain amplifiers and filters for adjusting the phase and amplitude of the echo signal, and transmit paths return the echo signal to the radar source via the antenna elements. Echo signals may combine with those of other such devices, having various lengths and associated frequencies, to simulate a false return associated with a particular aircraft or moving target (e.g., simulation of Doppler shift via offset echo frequencies).

A deployable active radar countermeasure or smart chaff device includes a flexible battery or length of reflective material for passive reflection of a surveillance radar signal. Metallized antenna elements printed onto the material receive the surveillance radar signals, and RF integrated circuitry bonded to the material generates active RF echo signals based on the frequency of the surveillance signal and the length of the material. Wirebond receiving paths include reconfigurable gain amplifiers and filters for adjusting the phase and amplitude of the echo signal, and transmit paths return the echo signal to the radar source via the antenna elements. Echo signals may combine with those of other such devices, having various lengths and associated frequencies, to simulate a false return associated with a particular aircraft or moving target (e.g., simulation of Doppler shift via offset echo frequencies).