Microelectromechanical tunable delay line circuit
Tunable delay circuit devices have an input port, an output port, at least three parallel paths connecting the input port and the output port, on each path, an input switch and an output switch, and on each path, a plurality of shunt resonant tanks connected between the input switch and the output switch, each shunt resonant tank periodically chargeable from the input port and dischargeable to the output port by operation of the input switch and the output switch.
1. A tunable delay circuit device comprising:
an input port;
an output port;
at least three parallel paths connecting the input port and the output port;
on each path, an input switch and an output switch; and
on each path, a plurality of shunt resonant tanks connected between the input switch and the output switch, each shunt resonant tank periodically chargeable from the input port and dischargeable to the output port by operation of the input switch and the output switch;
wherein each of the shunt resonant tanks includes at least one of:
a thin-film piezoelectric resonator; or
a piezoelectric layer, a first conductive material layer comprising at least a first electrode on a top surface of the piezoelectric layer, and a second conductive material layer comprising at least a second electrode on a bottom surface of the piezoelectric layer.
2. The device of claim 1 , wherein the shunt resonant tank further comprises a periodically modulated microelectromechanical (MEMS) resonator or an LC tank.
3. The device of claim 1 , wherein the input switches and the output switches on each path are periodically modulated with a duty cycle to cover an entire modulation period.
4. The device of claim 1 , wherein each of the plurality of shunt resonant tanks having a different center frequency.
5. The device of claim 4 , wherein the different center frequencies of the plurality of shunt resonant tanks are equally spaced with respect to each other by three times a modulation frequency of the device.
6. The device of claim 1 , further comprising:
a first matching inductor connected between the input port and the at least three parallel paths; and
a second matching inductor connected between the output port and the at least three parallel paths.
7. The device of claim 5 , wherein each path includes seven shunt resonant tanks.
8. The device of claim 5 , wherein the modulation frequency is 20 MHz.
9. The device of claim 3 , further comprising circuitry in communication with the input and output switches to operate each of the input and output switches at a selected modulation period and a selected duty cycle.
10. The device of claim 9 , wherein the modulation period is comparable to a time constant of the shunt resonant tanks.
11. The device of claim 9 , wherein the duty cycle is selected based on a number of the shunt resonant tanks.
12. The device of claim 2 , wherein each shunt resonant tank includes an electromechanical resonator or a resonant circuit.
13. The device of claim 12 , wherein the resonant circuit includes a capacitor bank, back to back varactors, or reconfigurable resonators.
14. The device of claim 1 , wherein the piezoelectric layer is a piezoelectric material selected from the group consisting of quartz, aluminum nitride, doped aluminum nitride, lithium niobate, lithium tantalite, zinc oxide, and gallium nitride.
15. The device of claim 1 , wherein each input switch and output switch comprises a single pole single throw switch or a single pole double throw switch.
16. A method of operating a tunable delay circuit device comprising, providing the tunable delay circuit device including:
an input port;
an output port;
at least three parallel paths connecting the input port and the output port;
on each path, an input switch and an output switch; and
on each path, a plurality of shunt resonant tanks connected between the input switch and the output switch;
the method comprising:
operating the input and output switches to periodically charge each shunt resonant tank from the input port; and
operating the input and output switches to periodically discharge each shunt resonant tank to the output port; and introducing three low-loss poles into the device for each of the plurality of shunt resonant tanks.