[1] [1] PENG R, SICHITIU M L. Angle of arrival localization for wireless sensor networks[C]//2006 3rd Annual IEEE Communications Society on Sensor and Ad Hoc Communications and Networks, September 28-28, 2006, Reston, USA. Reston: IEEE, 2006: 374-382.

[2] [2] NICULESCU D, NATH B. Ad hoc positioning system （APS） using AOA[C]//IEEE. Twenty-second Annual Joint Conference of the IEEE Computer and Communications Societies （IEEE Cat. No.03CH37428）, March 30-April 3, 2016, San Francisco, USA. Piscataway: IEEE, 2003: 1734-1743.

[4] [4] STOICA P, SHARMAN K C. Maximum likelihood methods for direction-of-arrival estimation[J]. IEEE Transactions on Acoustics, Speech, and Signal Processing, 1990, 38（7）: 1132-1143.

[5] [5] CAPMANY J, NOVAK D. Microwave photonics combines two worlds[J]. Nature Photon, 2007（1）: 319-330.

[6] [6] YAO J P. Microwave Photonics[J]. Journal of Lightwave Technology, 2009, 27（3）: 314-335.

[7] [7] ZOU X H, LU B, PAN W, et al. Photonics for microwave measurements[R]. Laser & Photonics Reviews, 2016（10）: 711-734.

[10] [10] HUANG C J, CHAN E. Multichannel microwave photonic based direction finding system[J]. Optics Express, 2020, 28（17）: 25346-25357.

[11] [11] ZHANG Z X, CHEN M H, GUO Q, et al. Photonic mixing approach to measure the angle-of-arrival of microwave signals[C]//Conference on Lasers and Electro-Optics （CLEO）, June 5-10, 2016, San Jose, USA. Piscataway: IEEE, 2016: 243-245.

[12] [12] LI P, YAN L S, YE J, et al. Angle-of-arrival estimation of microwave signals based on optical phase scanning[J]. Journal of Lightwave Technology, 2019, 37（24）: 6048-6053.

[13] [13] MA Q, ZHAO X, CAO Z, et al. Accuracy monitoring and enhancement for microwave localization using parallel optical delay detector[J]. Optics Communications, 2019, 439: 94-98.

[14] [14] CAO Z Z, WANG Q, LU R G, et al. Angle-of-arrival measurement of a microwave signal using parallel optical delay detector[J]. IEEE Photonics Technology Letters, 2013, 25（19）: 1932-1935.

[15] [15] ZHUO H, WEN A J, WANG Y. Photonic angle-of-arrival measurement without direction ambiguity based on a dual-parallel Mach-Zehnder modulator[J]. Optics Communications, 2019, 451: 286-289.

[16] [16] LIN T, ZHANG Z K, WANG Y H, et al. Photonic 2-D angle-of-arrival estimation based on an L-shaped antenna array for an early radar warning receiver[J]. Optics express, 2020, 28（26）: 38960-38972.

[17] [17] CHEN H, CHAN E. Angle-of-arrival measurement system using double RF modulation technique[J]. IEEE Photonics Journal, 2019, 11（1）: 1-10.

[18] [18] CHEN H, HUANG C, CHAN E. Photonic approach for measuring AOA of multiple signals with improved measurement accuracy[J]. IEEE Photonics Journal, 2020, 12（3）: 7201810-1-7201810-10.

[19] [19] CHEN H, CHAN E. Simple approach to measure angle of arrival of a microwave signal[J]. IEEE Photonics Technology Letters, 2019, 31（22）: 1795-1798.

[20] [20] YANG Y, MA C, ZHANG F Z, et al. Photonics-based simultaneous angle of arrival and frequency measurement for multiple targets detection[C]// 2020 International Topical Meeting on Microwave Photonics（MWP）,November 24-26, 2020, ELECTR NETWORK. Piscataway: IEEE, 2020: 14-17.

[21] [21] VIDAL B, PIQUERAS M A, MARTI J. Direction-of-arrival estimation of broadband microwave signals in phased-array antennas using photonic techniques[J]. Journal of Lightwave Technology, 2006, 24（7）: 2741-2745.

[22] [22] TU Z Y, WEN A J, XIU Z G, et al. Angle-of-Arrival Estimation of Broadband Microwave Signals Based on Microwave Photonic Filtering[J]. IEEE Photonics Journal, 2017, 9（5）: 5503208-1-5503208-8.

[24] [24] WANG Y X, HOU X Y, LI T, et al. Simultaneous detection of the distance and direction for a noncooperative target based on the microwave photonic radar[J]. Opt Express, 2021, 29（20）: 31561-31573.

[25] [25] LI S Y, CAO H D, ZHENG X P. Concurrent photonic measurement of angle-of-arrival and chirp rate of microwave LFM signal[J]. Chinese Optics Letters, 2020, 18（12）: 123902-1-123902-5.