Quasi active MIMIC circulator

1. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broadband performance comprising:

an antenna port;

a transmission port;

a receiving port;

wherein each port is connected to a 90 degree combiner/divider for splitting an input signal into two output components, the said output components have a ninety degrees relative phase difference to each other;

each of said 90 degree combiner/dividers in addition to the connection to the above mentioned ports has at least two output connections each of which are connected to a Y-junction and if a fourth connection, said fourth connection is attached to a matching load circuit;

this arrangement of circuits allows the portion of the phase shifted signals from the transmit port to enter the antenna 90 degree combiner/divider and be recombined in phase at the antenna port, while the rest of the signal enters the receive 90 degree combiner/divider and are phase cancelled;

said arrangement simultaneously allows the receive signal entering the antenna port and proceeding to the antenna 90 degree combiner/divider to enter the receive 90 degree combiner/divider and to be combined in phase at the receive port.

2. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broadband performance as described in claim 1 further comprising unilateral devices such as: field effect transistors, bipolar junction transistors, amplifier or any devices with high reverse isolation located between said 90 degree combiner/divider at the transmit port and said Y-junctions to prevent any signals from returning to said transmit port.

3. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance as described in claim 1 wherein a Lange coupler is substituted for said 90 degree divider/combiner.

4. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance as described in claim 1 wherein said 90 degree divider/combiner is substituted by active circuitries using field effective transistors, bipolar junction transistors, or any other MMIC devices that are similar in operation to said 90 degree combiner/divider.

5. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance described in claim 1 further comprising an amplifier inserted to the circuitry after the transmit port but before the 90 degree combiner/divider.

6. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance described in claim 1 further comprising an amplifier inserted to the circuitry after the transmit port but before the 90 degree combiner/divider and a unilateral device inserted after the 90 degree combiner/divider, but before the Y-junction.

7. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance described in claim 1 further comprising an balanced amplifier inserted to the circuitry after the transmit port but before the said transmit 90 degree combiner/divider.

8. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance described in claim 1 further comprising a low noise amplifier inserted into the circuitry between the receive said receive 90 divider/combiner and the receive port.

9. A circulator capable of simultaneous transmit and receive operations, high frequency, high isolation and broad band performance described in claim 1 further comprising a balanced low noise amplifier inserted into the circuitry between said receive 90 divider/combiner and said receive port.

10. A circulator capable of simultaneous transmit and receive operations high frequency and broad band performance as described in claim 1 further comprising a forward cancellation circuit and a low noise amplifier;

said forward cancellation circuit is connected to said circulator by couplers;

the first of said couplers is located between the amplifier and the transmit port;

the other of said couplers is located between the receive port and the input port of said low noise amplifier;

said forward cancellation circuit is also comprised of an attenuator.

11. A circulator capable of simultaneous transmit and receive operations, high frequency, and broad band performance as described in claim 1 further comprising an amplifier after the transmit port but before the 90 degree divider/combiner and a low noise amplifier after the receive 90 degree divider/combiner but before the receive port.

12. A circulator capable of simultaneous transmit and receive operations, high frequency, and broad band performance as described in claim 1 further comprising an amplifier after the transmit port but before the 90 degree divider/combiner and a balanced low noise amplifier after the receive 90 degree divider/combiner but before the receive port; said balanced low noise amplifier includes Lange couplers.

13. A circulator capable of simultaneous transmit and receive operations, high frequency, and broad band performance as described in claim 1 further comprising a balanced amplifier after the transmit port but before the 90 degree divider/combiner and a balanced low noise amplifier after the receive 90 degree divider/combiner but before the receive port; said balanced amplifier includes balance structure that uses Lange couplers; said balanced low noise amplifier includes balance structure that uses Lange couplers; said device may or may not include unilateral devices.