N25A-T018 TITLE: High-Power Microwave Phase Shifter

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Materials;Directed Energy (DE);Microelectronics

OBJECTIVE: Develop a high-power phase shifter and feed network in X-band capable of withstanding peak powers of above 100 MW and pulse durations of threshold of at least 10 ns with an objective of 200ns. The phase shifter ideally would be capable of operating within a fraction of a frequency band aligned to available waveguide, have insertion loss of < 0.5 dB with 0 – 360° phase control. The device should be sealed sufficient to maintain high vacuum which would be maintained by pumps located elsewhere along the connecting waveguides. The device should have a tuning agility to move across 180 degrees in less than 100 ms and have a tuning resolution better than 1 degree.

DESCRIPTION: Microwave phase shifters are commonly used for phase steering arrayed antennas but do not operate at the typical peak powers seen in High Power Microwave (HPM) systems. HPM sources may produce output powers of several GW which can be divided and fed to an arrayed antenna network. These sources are typically operated at high vacuum (< 10-5 torr) along with the output antenna and waveguide networks for insulation purposes. At such vacuum levels, field stresses up to 80 MV/m are tolerable for the short durations produced by these source technologies.

HPM sources in this regime have bandwidths less than 1% of the center frequency for any output pulse and 3 dB pulse widths less than 50 ns. In some instances, multiple or tunable sources may be used which have varying output frequencies from shot to shot, each with the sub 1% bandwidth.

HPM systems in this regime typically operate with maximum repetition frequencies of a 10s to 100s of Hz for burst durations around a second. If the tuning agility is sufficiently fast, it may be possible to adjust the phase of the antenna elements from shot to shot within a burst.

Based on these considerations, the following design requirements should be considered for the phase shifter:

• Input Power: 100 MW or greater

• Pulse duration: 10 ns to 200 ns

• Operational frequency: X-Band

• Bandwidth: 1% or more of design frequency

• Vacuum: < 10-5 torr

• Tuning resolution: < 1 degree

• Tuning agility: 1.8 degree / ms

• Phase control range: 0-360 degree

• Insertion loss of < 0.5 dB

• Minimize electrical scale of the component

• Minimize cost per device

PHASE I: Develop and numerically simulate a design demonstrating the performance capabilities of the phase shifter that meet the requirements above. Build scaled proof-of-concept hardware to validate modeling. Provide a plan for the Phase II effort.

PHASE II: In consultation with ONR, proceed to fabrication of a phase shifter to be tested at full power using government provided source hardware. In addition to single element testing construct a sub array of as few as 16 elements for testing of steering capability. Document the performance and design of the developed hardware and sub array.

PHASE III DUAL USE APPLICATIONS: HPM weapons of both defensive and offensive designs could utilize a developed phase shifter to integrate on a number of candidate platforms. In addition, HPM technology is also usable in high-power radar and the Electronic Attack (EA) subsystems for Electronic Warfare (EW). In consultation and with ONR approval, proceed to building multiple phase shifters to integrate into a full phased steered HPM system utilizing an arrayed antenna provided by the government. Implement a control system to coordinate the phase shifters. Extensive commercial applications include phased array antennas for radar systems, satellite communications and 5G networks with additional applications in test/measurement equipment for RF systems and medical devices.

REFERENCES:

Changing Waveguide Side Wall Dimensions

1. Zhuang, QQ.; Yan, F.; Jiang, Z.; Liu, M.; Xiong, Z. and Yan, C. "Study and Design of A Contracting Waveguide Phase Shifter for S-band High-Power Microwave Applications." 2019 IEEE 2nd International Conference on Electronics Technology (ICET), Chengdu, China, 2019, pp. 162-165. doi: 10.1109/ELTECH.2019.8839350

2. Yang, Y. -M.; Yuan, C. W.; Cheng, C. X. and Qian, B. L. "Ku-Band Rectangular Waveguide Wide Side Dimension Adjustable Phase Shifter." IEEE Transactions on Plasma Science, vol. 43, no. 5, May 2015, pp. 1666-1669. doi: 10.1109/TPS.2014.2370074

3. Yang, Y. -M.; Yuan, C. W. and Qian, B. L. "A Novel Phase Shifter for Ku-Band High-Power Microwave Applications." IEEE Transactions on Plasma Science, vol. 42, no. 1, Jan. 2014, pp. 51-54. doi: 10.1109/TPS.2013.2288946

Reflector-Based Phase Shifter (3 types seen)

4. Liu, A.; Lu, J.; Tan, P. K.; Gan, T. H. and Sow, S. M. "A Compact Waveguide-Based Reflection-Type Phase Shifter." 2021 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (APS/URSI), Singapore, Singapore, 2021, pp. 1633-1634. doi: 10.1109/APS/URSI47566.2021.9704049

5. Chang, C. et al. "A New Compact High-Power Microwave Phase Shifter." IEEE Transactions on Microwave Theory and Techniques, vol. 63, no. 6, June 2015, pp. 1875-1882. doi: 10.1109/TMTT.2015.2423281

6. Guo, L. t.; Chang, C.; Huang, W. h.; Sun, J. and Liu, Y.s. "Design of a novel phase shifter for high power microwave applications." 2015 IEEE International Vacuum Electronics Conference (IVEC), Beijing, China, 2015, pp. 1-2. doi: 10.1109/IVEC.2015.7223835

7. Choi, J. -H. and Kim, Y. -H. "A High-Power Waveguide Phase Shifter With Periodic RF Chokes for Subgigawatt NanopulseTransmission." IEEE Transactions on Plasma Science, vol. 44, no. 10, Oct. 2016, pp. 2307-2313. doi: 10.1109/TPS.2016.2600032

Phase Shifters Leveraging Polarization (includes Refs 4-6 above)

8. Zhao, X. -L.; Yuan, C. W.; Liu, L.; Peng, S. R.; Bai, Z. and Cai, D. "GW TEM-Mode Phase Shifter for High-Power Microwave Applications." IEEE Transactions on Plasma Science, vol. 44, no. 3, March 2016, pp. 268-272. doi: 10.1109/TPS.2016.2523122

Movable Gaps/Holes/Objects in Waveguide

9. Wang, E.; Yang, J. and Zaman, A. U. "An E-band Reconfigurable Phase Shifter Based on Gap Waveguide." 2022 16th European Conference on Antennas and Propagation (EuCAP), Madrid, Spain, 2022, pp. 1-3. doi: 10.23919/EuCAP53622.2022.9769484

10. Palomares-Caballero, Á.; Alex-Amor, A.; Padilla, P. and Valenzuela-Valdés, J. F. "Reconfigurable Phase Shifter in Waveguide Technology Based on Glide-Symmetric Holey Structures." 2021 15th European Conference on Antennas and Propagation (EuCAP), Dusseldorf, Germany, 2021, pp. 1-4.

11. Zhang, Q.; Yuan, C. and Liu, L. "Studies on mechanical tunable waveguide phase shifters for phased-array antenna applications." 2016 IEEE International Symposium on Phased Array Systems and Technology (PAST), Waltham, MA, USA, 2016, pp. 1-3.

12. Yokokawa, K. et al. "Study on reconfigurable corrugated waveguide using moveable shorting plate." 2017 IEEE Conference on Antenna Measurements & Applications (CAMA), Tsukuba, Japan, 2017, pp. 49-50.

13. Ghasemi, A. and Laurin, J. J. "X-band waveguide phase shifter using rotating dielectric slab," 2016 IEEE International Symposium on Antennas and Propagation (APSURSI), Fajardo, PR, USA, 2016, pp. 1139-1140.

KEYWORDS: High Power Microwave; HPM; Microwave; Phase shifter; Electromagnetic; Beam-steering; Antenna

TPOC 1: Ryan Hoffman
Email: [email protected]

TPOC 2: Jordan Chaparro
Email: [email protected]

---