Method and an apparatus for decoupling multiple antennas in a compact antenna array

An apparatus for decoupling a plurality of antennas in an antenna array, wherein the plurality of antennas transmit and receive signals via respective one of a plurality of input/output ports, the device comprises:

• a plurality of adjusting devices, each of which connected between a respective antenna of the plurality of antennas and a respective one input/output port of the plurality of input/output ports;
• and
• one or more decoupling networks connected between the respective input/output ports of the plurality of input/output ports,
• wherein the plurality of adjusting devices are configured to have an admittance adjustable to compensate an admittance of the decoupling networks such that an isolation coefficient between the input/output ports approaches zero as well as reflection coefficients of each input/output port are minimized,
• wherein each of the decoupling networks comprise:
• a Coupled Resonator Decoupling Network (CRDN) nodule;
• a first I/O coupling module connected between the first input/output port and the CRDN module;
• and
• a second I/O coupling module connected between the second input/output port and the CRDN module;
• wherein the first and second I/O coupling modules have adjustable electrical parameters such that the decoupling networks have an adjustable working frequency and an adjustable decoupling level.

A method for decoupling two antennas in an antenna array, wherein the two antennas transmit and receive signals via a first input/output port and a second input/output port, the method comprising:

• inserting a first adjusting device between a first antenna of the two antennas and the first input/output port;
• inserting a second adjusting device between a second antenna of the two antennas and the second input/output port;
• connecting one or more decoupling networks between the first input/output port and the second input/output port;
• and
• adjusting an admittance of each of the first and the second adjusting devices to compensate an admittance of the decoupling networks such that an isolation coefficient between the two input/output ports approaches zero as well as reflection coefficients of each input/output port are minimized,
• wherein each of the decoupling networks comprises a Coupled Resonator Decoupling Network (CRDN), a first I/O coupling module and a second I/O coupling module, the method further comprises:
• inserting the first I/O coupling module between the first input/output port and the CRDN module;
• inserting the second I/O coupling module between the second input/output port and the CRDN module;
• and
• adjusting electrical parameters of the first and second I/O coupling modules such that the decoupling networks have an adjustable working frequency and an adjustable decoupling level.

An apparatus for decoupling two antennas in an antenna array, wherein the two antennas transmit and receive signals via a first input/output port and a second input/output port of the apparatus, and the apparatus comprises:

• a first adjusting device connected between a first antenna of the two antennas and the first input/output port;
• a second adjusting device connected between a second antenna of the two antennas and the second input/output port;
• and
• one or more decoupling networks connected between the first input/output port and the second input/output port, each of which comprises:
• a Coupled Resonator Decoupling Network (CRDN) module;
• a first I/O coupling module connected between the first input/output port and the CRDN module;
• and
• a second I/O coupling module connected between the second input/output port and the CRDN module;
• wherein, the first and second I/O coupling modules have adjustable electrical parameters such that the decoupling networks have an adjustable working frequency and an adjustable decoupling level,
• wherein the first and the second adjusting devices are configured to have an electrical length and characteristic impedance, both of which are adjustable to compensate the admittance of the decoupling networks, such that an isolation coefficient between the two input/output ports approaches zero as well as reflection coefficients of each input/output port are minimized.