Integrated energy harvesting transceivers and transmitters with dual-antenna architecture for miniaturized implants and electrochemical sensors
Systems and methods for utilizing a small form-factor, wirelessly powered transceiver are disclosed. In one embodiment, a wireless powered transceiver includes a receive antenna configured to receive a receive signal, a transmit antenna configured to transmit a transmit signal, a power harvesting system including a rectifier circuit configured convert radio frequency energy from the receive signal into DC (direct current) voltage, and a power management unit (PMU) configured to set the operating mode and biasing condition of the receive and transmit circuitry blocks and provide DC voltage from the receive circuitry block to the transmit circuitry block to maintain a minimum voltage, a receiver circuitry block configured to provide energy from the receive signal to the power harvesting system, and a transmitter circuitry block including a data modulator circuit, the data modulator circuit configured to generate the transmit signal using DC voltage received from the power management unit.
1. A small form-factor, wirelessly powered transceiver on a chip, the transceiver comprising:
a receive antenna on the chip and comprising a loop antenna configured to receive a receive signal;
a transmit antenna on the chip and at least partially surrounding the receive antenna and configured to transmit a transmit signal; and
a power harvesting system comprising:
a rectifier circuit configured to convert radio frequency energy from the receive signal into DC (direct current) voltage; and
a power management unit (PMU);
a receiver circuitry block configured to provide energy from the receive signal to the power harvesting system; and
a transmitter circuitry block comprising a data modulator circuit, the data modulator circuit configured to generate the transmit signal using DC voltage received from the power management unit;
wherein the PMU is configured to set an operating mode and biasing condition of the receiver and transmitter circuitry blocks and to provide DC voltage from the receiver circuitry block to the transmitter circuitry block to maintain a minimum voltage.
2. The wirelessly powered transceiver of claim 1 , wherein the rectifier circuit comprises four full-wave rectifiers.
3. The wirelessly powered transceiver of claim 1 , wherein the rectifier circuit comprises an on-chip coil (OCC).
4. The wirelessly powered transceiver of claim 1 , wherein the receive antenna further comprises a capacitor.
5. A small form-factor, wirelessly powered transceiver comprising:
a receive antenna configured to receive a receive signal;
a transmit antenna configured to transmit a transmit signal; and
a power harvesting system comprising:
a rectifier circuit configured to convert radio frequency energy from the receive signal into DC (direct current) voltage;
a power management unit (PMU);
a receiver circuitry block configured to provide energy from the receive signal to the power harvesting system; and
a transmitter circuitry block comprising a data modulator circuit, the data modulator circuit configured to generate the transmit signal using DC voltage received from the power management unit;
wherein the receiver circuitry block further comprises a tunable capacitor configured to change the resonance frequency of the receive antenna to reduce interference with the transmit signal;
wherein the PMU is configured to set an operating mode and biasing condition of the receiver and transmitter circuitry blocks and to provide DC voltage from the receiver circuitry block to the transmitter circuitry block to maintain a minimum voltage.
6. The wirelessly powered transceiver of claim 1 , where the transmitter circuitry block comprises a power oscillator.
7. The wirelessly powered transceiver of claim 6 , wherein the receiver circuitry block is configured to extract a clock signal from the receive signal and the transmitter circuitry block is configured to synchronize the power oscillator to the clock signal.
8. The wirelessly powered transceiver of claim 1 , where the transmitter circuitry block comprises an LC oscillator and power amplifier.
9. The wirelessly powered transceiver of claim 1 , further comprising a bioelectrical signal sensor configured to generate a bioelectrical signal to the data modulator circuit.
10. The wireless powered transceiver of claim 9 , wherein the bioelectrical signal sensor is a neural LFP (local field potential) sensor.
11. The wirelessly powered transceiver of claim 1 , wherein the power management unit includes a low dropout voltage regulator (LDO) configured to change its bias current based upon a sleep and an active state of the transmitter circuitry block.
12. A small form-factor, wirelessly powered transceiver comprising:
a receive antenna configured to receive a receive signal;
a transmit antenna configured to transmit a transmit signal; and
a power harvesting system comprising:
a rectifier circuit configured to convert radio frequency energy from the receive signal into DC (direct current) voltage;
a power management unit (PMU);
a receiver circuitry block configured to provide energy from the receive signal to the power harvesting system; and
a transmitter circuitry block comprising a data modulator circuit, the data modulator circuit configured to generate the transmit signal using DC voltage received from the power management unit;
wherein the receiver circuitry block comprises a data demodulator configured to extract a receive message from the receive signal;
wherein the PMU is configured to set an operating mode and biasing condition of the receiver and transmitter circuitry blocks and to provide DC voltage from the receiver circuitry block to the transmitter circuitry block to maintain a minimum voltage.
13. The wirelessly powered transceiver of claim 1 , wherein the receiver circuitry block and transmitter circuitry block are configured to operate at different frequencies.
14. The wirelessly powered transceiver of claim 1 , wherein the receiver circuitry block and transmitter circuitry block utilize amplitude-based modulation schemes in the receive signal and transmit signal.
15. The wirelessly powered transceiver of claim 14 , wherein the receiver circuitry block utilizes amplitude-shift-keying (ASK) modulation for receiving data in the receive signal and the transmitter circuitry block utilizes frequency divisional duplexing (FDD) for transmitting data in the transmit signal.
16. The wirelessly powered transceiver of claim 1 , where the PMU is configured to control the transmitter circuitry block to operate on a duty cycle based upon a current amount of energy stored in a storage capacitor, by deactivating the transmitter circuitry block when voltage across the storage capacitor falls below a lower threshold voltage and activating the transmitter circuitry block when voltage across the storage capacitor exceeds a higher threshold voltage.
17. The wirelessly powered transceiver of claim 1 , wherein the transmit antenna is a dipole antenna.
18. The wirelessly powered transceiver of claim 1 , wherein the transmit antenna dimensions and operating frequency are optimized to minimize interference from operation of the receive antenna.
19. The wirelessly powered transceiver of claim 1 , further comprising an electrochemical sensor configured to generate an electrochemical signal to the data modulator circuit.
20. The wirelessly powered transceiver of claim 19 , wherein the electrochemical sensor is a pH sensor configured to provide an electrochemical signal indicative of pH of a solution.
21. The wirelessly powered transceiver of claim 1 , wherein the transmit signal can be received as multiple reads and localization of the transceiver is determined from the multiple reads.
22. The wirelessly powered transceiver of claim 21 , wherein the localization accuracy is improved by moving the location of the transceiver and repeating the measurement.
23. The wirelessly powered transceiver of claim 22 , wherein the localization accuracy is improved by utilizing the phase and amplitude of the read signal as a function of the location of the transceiver.