Frequency offset using SiGe phase shifters
A radar system for interacting with navigation targets is provided. The radar system is configured to interact with navigation targets (target devices) that shift the phase of a received radar transmission to generate a phase shifted response signal. Phase shifters (e.g., silicon germanium phase shifters) are designed to assign specific frequency responses from one or more navigation modules to identify target locations. The radar module transmits at a modulated signal at first frequency, each navigation target receives the radar transmission, phase shifts the signal and returns the phase shifted signal. Where two or more navigation targets are used, each will apply a different phase shift to the received radar transmission, wherein the frequency identifies the navigation target devices. In a radar system, the modulated transmission signal is compared to the returned phase shifted signal to determine a frequency difference between the two signals.
1. A navigation target device for medical application, comprising:
a receive antenna configured to receive a radar transmission from a radar system, the radar transmission from an anatomical portion of a person and configured to align different locations;
a transmit antenna configured to transmit a response signal based on the received radar transmission;
a phase shifter module coupled between the receive antenna and the transmit antenna and adapted to identify the different locations; and
a controller configured to apply a first voltage of a plurality of voltages to the phase shifter module, the first voltage corresponding to a first phase shift value, and the first phase shift value enables identification of the navigation target device from one or more other navigation target devices and to identify the location of the anatomical portion of the person associated with the navigation target device,
wherein the phase shifter module is configured to apply the first phase shift value to the received radar transmission and generate the response signal corresponding to identification of the navigation target device from the one or more other navigation target devices, and
wherein the navigation target device is encapsulated in a biocompatible shell.
2. The navigation target device of claim 1 , wherein the first phase shift value corresponds to a first frequency that identifies the navigation target device.
3. The navigation target device of claim 1 , wherein the phase shifter module comprises a silicon germanium (SiGe) phase shifter.
4. The navigation target device of claim 1 , wherein the navigation target device is part of an operational system that is configured to work with the radar system for a medical environment.
5. The navigation target device of claim 1 , wherein the first phase shift value is based on a predetermined lookup table stored within the controller.
6. The navigation target device of claim 1 , further comprising a balun and a variable gain antenna.
7. The navigation target device of claim 1 , further comprising one or more radio frequency integrated circuits (RFICs).
8. The navigation target device of claim 1 , wherein the navigation target device is implantable.
9. A radar system, comprising:
a radar module adapted to transmit modulated radar signals, the radar module comprising:
a radar module receive antenna configured to receive signals from an anatomical portion of a person and configured to align different locations,
a radar module transmit antenna,
a range-Doppler processor, and
a radar controller;
at least one navigation target positioned proximate the radar module, comprising:
a navigation target receive antenna configured to receive a radar transmission from the radar module,
a navigation target transmit antenna configured to transmit a response signal based on the received radar transmission,
a phase shifter module coupled between the navigation target receive antenna and the navigation target transmit antenna, and
a navigation target controller adapted to apply a first voltage of a plurality of voltages to the phase shifter module, the first voltage corresponding to a first phase shift value, and the first phase shift value enables identification of the at least one navigation target from one or more other navigation targets and to identify the location of the anatomical portion of the person associated with the at least one navigation target,
wherein the phase shifter module is adapted to apply the phase shift value to the received radar transmission and generate the response signal corresponding to identification of the at least one navigation target from the one or more other navigation targets; and
a surgical interface in communication with the radar module configured to provide information comprising a location of the at least one navigation target.
10. The radar system of claim 9 , wherein the radar module identifies the at least one navigation target by a response signal Doppler frequency.
11. The radar system of claim 9 , wherein the radar system is used for a medical procedure.
12. The radar system of claim 9 , wherein the at least one navigation target comprises a first navigation target that applies the first phase shift value to the received radar transmission and a second navigation target that applies a second phase shift value to the received radar transmission.
13. The radar system of claim 12 , wherein the first navigation target and the second navigation target are positioned in a configuration for acquiring locations of the first navigation target and the second navigation target via a geometric position triangulation.
14. The radar system of claim 12 , wherein the first phase shift value and the second phase shift value are stored in a predetermined lookup table stored within the navigation target controller.
15. The radar system of claim 9 , wherein the at least one navigation target is implantable and is encapsulated in a biocompatible shell.
16. A method of using a navigation target device, comprising:
receiving, at a receive antenna configured to align different anatomical portions of a person or a vehicle, a radio frequency (RF) signal from a radar system;
processing the RF signal from the receive antenna;
applying, via a SiGe phase shifter, a voltage value of a plurality of voltage values to the RF signal thereby phase shifting the RF signal by a first phase shift value corresponding to the voltage value, wherein the first phase shift value enables identification of the navigation target device from one or more other navigation target devices and to identify the location of the anatomical portion of the person associated with the navigation target device; and
transmitting, via a transmit antenna, the phase shifted RF signal, wherein the phase shifted RF signal corresponds to identification of the navigation target device from the one or more other navigation target devices,
wherein the navigation target device is encapsulated in a biocompatible shell.
17. The method of claim 16 , wherein the voltage value is based on a predetermined lookup table stored within the navigation target device.
18. The method of claim 16 , wherein the phase shifting is performed by a radio frequency integrated circuit (RFIC) based on a predetermined lookup table.
19. The method of claim 16 , wherein the navigation target device is part of an operational system that is configured to work with the radar system for a medical environment and the phase shifted RF signal identifies the navigation target device.
20. The method of claim 16 , wherein the navigation target device is disposed in an anatomical portion of a body for tracking during a medical procedure.