Switched coupled inductance phase shift mechanism
Examples disclosed herein relate to a switched coupled inductance phase shift mechanism for beamsteering an antenna array and applied in a radar system or a communication system. The phase shift mechanism includes a variable inductor element configured to toggle between a first inductance state and a second inductance state in response to a first control bit value, and a plurality of variable capacitor elements coupled to the variable inductor element and configured to toggle between a first capacitance state and a second capacitance state in response to a second control bit value. The variable inductor element and the variable capacitor elements collectively produce a first phase shift using the first inductance and capacitance states, and collectively produce a second phase shift using the second inductance and capacitance states, where a target phase shift is produced from a difference between the first and second phase shifts. Other examples disclosed herein relate to an antenna array and a method of phase shifting with switched coupled inductance.
1. A radar device, comprising:
an antenna array;
a transceiver coupled to the antenna array;
an antenna controller adapted to steer radiation beams from the antenna array; and
a phase shift device, comprising:
a variable inductor element configured to toggle between a first inductance state and a second inductance state in response to a first control bit value; and
a plurality of variable capacitor elements coupled to the variable inductor element and configured to toggle between a first capacitance state and a second capacitance state in response to a second control bit value different from the first control bit value,
wherein the variable inductor element and the plurality of variable capacitor elements collectively produce a first phase shift using the first inductance state and the first capacitance state and collectively produce a second phase shift using the second inductance state and the second capacitance state, wherein a target phase shift is produced from a difference between the first phase shift and the second phase shift.
2. The radar device of claim 1 , wherein the first phase shift corresponds to a first steering direction and the second phase shift corresponds to a second steering direction.
3. The radar device of claim 2 , wherein the variable inductor element comprises a transformer and a first switch coupled to the transformer, wherein the transformer produces the first inductance state when the first switch is open, and wherein the transformer produces the second inductance state when the first switch is closed.
4. The radar device of claim 3 , wherein each of the plurality of variable capacitor elements comprises a first capacitor coupled in series with a second switch and a second capacitor coupled in parallel to the first capacitor and the second switch.
5. The phase shift device of claim 4 , wherein the first capacitor and the second capacitor collectively produce the first capacitance state when the second switch is closed and the first switch is open.
6. The phase shift device of claim 4 , wherein the first capacitor and the second capacitor collectively produce the second capacitance state when the second switch is open and the first switch is closed.
7. The radar device of claim 3 , wherein each of the plurality of variable capacitor elements comprises a first capacitor coupled in series with a second switch.
8. The radar device of claim 7 , wherein the first capacitor produces the first capacitance state when the second switch is closed and the first switch is open.
9. The radar device of claim 7 , wherein the first capacitor produces the second capacitance state when the second switch is open and the first switch is closed.
10. The radar device of claim 2 , wherein the variable inductor element comprises a transformer and a variable capacitor coupled to the transformer, wherein the transformer produces the first inductance state when the variable capacitor is applied with a first voltage, and wherein the transformer produces the second inductance state when the variable capacitor is applied with a second voltage different from the first voltage.
11. A beamsteering antenna system, comprising:
an array of radiating elements; and
a beamsteering controller coupled to the array of radiating elements and configured to apply phase shifting to transmit signaling directed to the array of radiating elements for a transmit operation and to return signaling from the array of radiating elements for a receive operation, the phase shift array comprising:
a plurality of phase shift circuits connected in series, each of the plurality of phase shift circuits comprising a lumped circuit with variable inductance and variable capacitance; and
a control mechanism coupled to the plurality of phase shift circuits and configured to control each of the plurality of phase shift circuits.
12. The beamsteering antenna system of claim 11 , wherein the beamsteering controller steers transmission signals in a specific direction having an azimuth angle and elevation angle with respect to boresight.
13. The beamsteering antenna system of claim 11 , wherein the lumped circuit comprises:
a variable inductor element configured to toggle between a first inductance state and a second inductance state in response to a first control bit value applied with the control mechanism; and
a plurality of variable capacitor elements coupled to the variable inductor element and configured to toggle between a first capacitance state and a second capacitance state in response to a second control bit value applied with the control mechanism, the second control bit value being different from the first control bit value,
wherein the variable inductor element and the plurality of variable capacitor elements collectively produce a first phase shift using the first inductance state and the first capacitance state and collectively produce a second phase shift using the second inductance state and the second capacitance state, wherein a target phase shift is produced from a difference between the first phase shift and the second phase shift.
14. The beamsteering antenna system of claim 11 , wherein the variable inductor element comprises a transformer and a first switch coupled to the transformer, wherein the transformer produces the first inductance state when the first switch is open, and wherein the transformer produces the second inductance state when the first switch is closed.
15. The beamsteering antenna system of claim 14 , wherein each of the plurality of variable capacitor elements comprises a first capacitor coupled in series with a second switch and a second capacitor coupled in parallel to the first capacitor and the second switch.
16. The beamsteering antenna system of claim 15 , wherein the first capacitor and the second capacitor collectively produce the first capacitance state when the second switch is closed and the first switch is open.
17. The beamsteering antenna system of claim 16 , wherein the first capacitor and the second capacitor collectively produce the second capacitance state when the second switch is open and the first switch is closed.
18. The beamsteering antenna system of claim 17 , wherein each of the plurality of variable capacitor elements comprises a first capacitor coupled in series with a second switch.
19. The beamsteering antenna system of claim 18 , wherein the first capacitor produces the first capacitance state when the second switch is closed and the first switch is open.
20. The beamsteering antenna system of claim 19 , wherein the first capacitor produces the second capacitance state when the second switch is open and the first switch is closed.