SWITCHABLE REFLECTIVE PHASE SHIFTER FOR MILLIMETER WAVE APPLICATIONS
Examples disclosed herein relate to a switchable reflective phase shifter for millimeter wave applications. The switchable reflective phase shifter has a switchable phase shift network with a plurality of switches to activate a plurality of phase subranges in response to a plurality of bias voltages provided by a control module, and a reflective phase shifter to generate phase shifts in a given phase subrange activated by a given switch in the plurality of switches.
1 . A switchable reflective phase shifter, comprising:
a switchable phase shift network comprising a plurality of switches to activate a plurality of phase subranges in response to a plurality of bias voltages provided by a control module; and
a reflective phase shifter to generate phase shifts in a given phase subrange activated by a given switch in the plurality of switches.
2 . The switchable reflective phase shifter of claim 1 , wherein the plurality of switches comprises a plurality of Single Pole, Three Throw (“SP3T”) switches triggered by the plurality of bias voltages provided by the control module.
3 . The switchable reflective phase shifter of claim 2 , wherein the plurality of SP3T switches comprises a first and a second SP3T switch coupled to a delay line of 120° and a delay line of 240°.
4 . The switchable reflective phase shifter of claim 1 , wherein the plurality of phase subranges comprises a first phase subrange from 0° to 120°, a second phase subrange from 120° to 240°, and a third phase subrange from 240° to 360°.
5 . The switchable reflective phase shifter of claim 1 , wherein the reflective phase shifter comprises a distributed varactor network implemented with a Lange coupler and a plurality of impedance lines.
6 . The switchable reflective phase shifter of claim 5 , wherein the Lange coupler is coupled to a first impedance line coupled to a first reflective load and a second impedance line coupled to a second reflective load.
7 . The switchable reflective phase shifter of claim 6 , wherein the first reflective load comprises a first and a second varactor coupled to a third impedance line.
8 . The switchable reflective phase shifter of claim 6 , wherein the second reflective load comprises a third and a fourth varactor coupled to a fourth impedance line.
9 . The switchable reflective phase shifter of claim 5 , wherein the reflective phase shifter reflects an RF signal distributed to the plurality of impedance lines with an increased phase range.
10 . A beam steering vehicle radar for object identification, comprising:
a radar module comprising at least one beam steering antenna and at least one RFIC implemented with a switchable reflective phase shifter to steer RF beams across a field-of-view and receive reflections of the steered RF beams; and
a perception module to receive radar data corresponding to the reflections of the steered RF beams and generate control instructions to adjust a steering of the RF beams.
11 . The beam steering vehicle radar of claim 10 , wherein the at least one beam steering antenna comprises a meta-structure antenna.
12 . The beam steering vehicle radar of claim 10 , wherein the radar module further comprises a transceiver to generate RF signals to be radiated as RF beams by the at least one beam steering antenna and to generate the radar data from the received reflections of the steered RF beams.
13 . The beam steering vehicle radar of claim 10 , wherein the switchable reflective phase shifter comprises a switchable phase shift network having a plurality of switches to activate a plurality of phase subranges based on a plurality of bias voltages and a reflective phase shifter to generate phase shifts in a given phase subrange activated by a given switch in the plurality of switches.
14 . The beam steering vehicle radar of claim 13 , wherein the reflective phase shifter comprises a distributed varactor network implemented with a Lange coupler and a plurality of impedance lines.
15 . The beam steering vehicle radar of claim 14 , wherein the reflective phase shifter reflects an RF signal distributed to the plurality of impedance lines with an increased phase range.
16 . The beam steering vehicle radar of claim 13 , wherein the control instructions comprise instructions to adjust the plurality of bias voltages.
17 . The beam steering vehicle radar of claim 10 , wherein the perception module comprises a machine learning module to detect and identify objects from the radar data.
18 . The beam steering vehicle radar of claim 17 , wherein the control data is generated based on the detection and identification of objects from the radar data.
19 . A method for steering RF beams in a beam steering vehicle radar for object detection and identification, comprising:
generating an RF signal for transmission;
providing a bias voltage to a switchable reflective phase shifter in the beam steering vehicle radar;
generating a phase shifted RF signal with a phase shift corresponding to the bias voltage, the phase shift in a first phase subrange;
radiating the phase shifted RF signal with a beam steering antenna to detect an object; and
switching the switchable reflective phase shifter to a second phase subrange based on the detected object.
20 . The method of claim 19 , further comprising providing control instructions to the beam steering vehicle radar to switch the switchable reflective phase shifter based on object detection data generated by a perception module upon detecting the object from a reflection of the phase shifted RF signal.