A microstrip mixer of a microwave-doppler detecting module has a shared port, a local oscillator signal input port and a mixing output port and includes two mixer tubes. The local oscillator signal input port is electrically connected with the shared port and is electrically connected with an end of one of the mixer tubes through the shared port. The local oscillator signal input port is also electrically connected with the mixing output port and is electrically connected with an end of the other mixer tube through the mixing output port. The other ends of the two mixer tubes are respectively grounded. Accordingly, the microstrip mixer is configured to have an open structure having three ports, which is more flexible and enhances the applicability thereof while reducing the size of the microwave-doppler detecting module utilizing the microstrip mixer.

The invention discloses a passive wideband mixer, including a local oscillator balun, a radio frequency balun, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, an inductive compensation unit, and a lossy inductive grounding network. The invention can realize a mixer with a bandwidth ratio of not less than 1:7, and can effectively suppress points with isolation deterioration without affecting the conversion loss over the entire frequency band. In the entire frequency band of this design, the isolation indicator between the local oscillator and radio frequency ports is optimized, which can well satisfy the application of the wideband mixer in a communication system.

The invention discloses a passive wideband mixer, including a local oscillator balun, a radio frequency balun, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, an inductive compensation unit, and a lossy inductive grounding network. The invention can realize a mixer with a bandwidth ratio of not less than 1:7, and can effectively suppress points with isolation deterioration without affecting the conversion loss over the entire frequency band. In the entire frequency band of this design, the isolation indicator between the local oscillator and radio frequency ports is optimized, which can well satisfy the application of the wideband mixer in a communication system.

A microstrip mixer of a microwave-doppler detecting module has a shared port, a local oscillator signal input port and a mixing output port and includes two mixer tubes. The local oscillator signal input port is electrically connected with the shared port and is electrically connected with an end of one of the mixer tubes through the shared port. The local oscillator signal input port is also electrically connected with the mixing output port and is electrically connected with an end of the other mixer tube through the mixing output port. The other ends of the two mixer tubes are respectively grounded. Accordingly, the microstrip mixer is configured to have an open structure having three ports, which is more flexible and enhances the applicability thereof while reducing the size of the microwave-doppler detecting module utilizing the microstrip mixer.

A microstrip mixer of a microwave-doppler detecting module has a shared port, a local oscillator signal input port and a mixing output port and includes two mixer tubes. The local oscillator signal input port is electrically connected with the shared port and is electrically connected with an end of one of the mixer tubes through the shared port. The local oscillator signal input port is also electrically connected with the mixing output port and is electrically connected with an end of the other mixer tube through the mixing output port. The other ends of the two mixer tubes are respectively grounded. Accordingly, the microstrip mixer is configured to have an open structure having three ports, which is more flexible and enhances the applicability thereof while reducing the size of the microwave-doppler detecting module utilizing the microstrip mixer.

A first phase shift circuit (2) converts impedance to achieve impedance matching between a third terminal (1c) of a 90-degree hybrid circuit (1) and a first terminal (4a) of a first nonlinear element (4), and shifts a phase of a radio wave by 180 degrees, and a second phase shift circuit (3) converts impedance to achieve impedance matching between a fourth terminal (1d) of the 90-degree hybrid circuit (1) and a first terminal (5a) of a second nonlinear element (5), and shifts a phase of a radio wave by 90 degrees. As a result of this configuration, a conversion loss of radio waves can be reduced.

A first phase shift circuit (2) converts impedance to achieve impedance matching between a third terminal (1c) of a 90-degree hybrid circuit (1) and a first terminal (4a) of a first nonlinear element (4), and shifts a phase of a radio wave by 180 degrees, and a second phase shift circuit (3) converts impedance to achieve impedance matching between a fourth terminal (1d) of the 90-degree hybrid circuit (1) and a first terminal (5a) of a second nonlinear element (5), and shifts a phase of a radio wave by 90 degrees. As a result of this configuration, a conversion loss of radio waves can be reduced.

Disclosed is an antenna-sub harmonic mixer block, which includes a dielectric block disposed on a PCB substrate having a ground surface, an antenna including first antenna patch provided on the dielectric block and having a metal patch and a slot, and a second antenna patch provided on the dielectric block, spaced apart from the first antenna patch to surround the first antenna patch, and that receives a ground voltage at the same potential as the ground surface of the PCB substrate, an RF ground wire disposed on the dielectric block and connected from the first antenna patch to a surface having the same potential as the ground surface, an RF switching stage disposed on the dielectric block, connected to the first antenna patch, and that provides a switching ON/OFF operation in conjunction with the RF ground wire depending on a magnitude of a local signal LO.

Disclosed is an antenna-sub harmonic mixer block, which includes a dielectric block disposed on a PCB substrate having a ground surface, an antenna including first antenna patch provided on the dielectric block and having a metal patch and a slot, and a second antenna patch provided on the dielectric block, spaced apart from the first antenna patch to surround the first antenna patch, and that receives a ground voltage at the same potential as the ground surface of the PCB substrate, an RF ground wire disposed on the dielectric block and connected from the first antenna patch to a surface having the same potential as the ground surface, an RF switching stage disposed on the dielectric block, connected to the first antenna patch, and that provides a switching ON/OFF operation in conjunction with the RF ground wire depending on a magnitude of a local signal LO.

An apparatus includes a first circuit and a second circuit. The first circuit may have a first diode and a second diode connected as anti-parallel diodes and physically adjacent to each other in a substrate. The second circuit may have a third diode and a fourth diode connected as anti-parallel diodes and physically adjacent to each other in the substrate. The first circuit and the second circuit may be configured to mix two input signals to generate an output signal. A polarity of every other physically neighboring diode may be reversed.