[1] M. I. Skolnik, “Radar Handbook,” 2ed, London: McGraw-Hill Publishing Co., Dec 1989. [2] M. M. Azer, S. I. Shams and A. M. M. A. Allam, “Compact double-sided printed omni-directional ultra wideband antenna,” IEEE Antennas and Propagation Society International Symposium, Toronto, ON, pp. 1-4, 2010. [3] H. H. Awadalla, S. I. Shams and A. M. M. A. Allam, “A compact, symmetric branched chain monopole for dual wide band operation,” 10th Mediterranean Microwave Symposium, Guzelyurt, pp. 56-59, 2010. [4] M. A. A. Fattah, A. M. M. A. Allam and S. I. Shams, “Irregular pentagon monopole structured antenna for ultra-wideband communication systems,” IEEE Middle East Conference on Antennas and Propagation (MECAP), Cairo, pp. 1-4, 2010. [5] M. A. Issa, M. H. Sharaf, S. I. Shams and A. M. M. A. Allam, “Stair-monopole antenna and irregular pentagon antenna in ultra wideband applications: Detailed study,” IEEE International Symposium on Antennas and Propagation (APSURSI), Spokane,WA, pp. 1766-1769, 2011. [6] M. Skolnik,“Introduction to Radar Systems,” 2 ed. New York: McGraw Hill Book Co., 1980. [7] C. A. Levis, J. T. Johnson, and F. L. Teixeira, Radiowave Propagation: Physics and Applications. Hoboken, NJ, USA: Wiley, 2010. [8] O. H. Hassan, S. I. Shams and A. M. M. A. Allam, “Dual-band circularly polarized antenna with CPW feeding structure,” Asia-Pacific Microwave Conference, Yokohama, pp. 2052-2055, 2010. [9] K. S. Mohamed, S. I. Shams and A. M. M. A. Allam, “Compact inset-fed microstripline circularly polarized antenna,” IEEE Middle East Conference on Antennas and Propagation (MECAP), Cairo, pp. 1-4, 2010. [10] G. B. Abdelsayed, S. I. Shams and A. M. M. A. Allam, “Triple-band circularly polarized slotted patch antenna for GPS and UMTS systems,” 10th Mediterranean Microwave Symposium, Guzelyurt, pp. 448-451, 2010. [11] M. A. Eldewiny, S. I. Shams and A. M. M. Allam, “A compact multiband planar antenna for DCS-1900/PCS/UMTS/WCDMA-2000/WLAN and WiMAX applications,” Asia-Pacific Microwave Conference, Yokohama, pp. 2060-2063, 2010. [12] Grebennikov, Andrei, “Power combiners, impedance transformers and directional couplers: part I.” High Frequency Electronics. vol. 6, pp. 20-38 December 2007. [13] S. I. Shams and A. A. Kishk, “Design of 3-dB Hybrid Coupler Based on RGW Technology,” in IEEE Transactions on Microwave Theory and Techniques, vol. 65, no. 10, pp. 3849-3855, Oct. 2017. [14] M. M. M. Ali, S. I. Shams and A. R. Sebak, “Printed Ridge Gap Waveguide 3-dB Coupler: Analy and Design Procedure,” in IEEE Access, vol. 6, pp. 8501-8509, 2018. [15] S. I. Shams and A. A. Kishk, “Wide band power divider based on Ridge gap waveguide,” 17th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), Montreal, QC, pp. 1-2, 2016. [16] Sean C. Ortiz, “High Power Spatial Combiners: Tile and Tray Approaches,” North Carolina State University, Department of Electrical Engineering, Raleigh, NC, 27695, 2001. [17] S. I. Shams, M. A. Abdelaal and A. A. Kishk, “SIW magic tee fed by printed Ridge Gap Waveguide design,” 17th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), Montreal, QC, pp. 1-2, 2016. [18] N. Hoven. “On the Feasibility of Cognitive Radio”, Master’s the University of California at Berkeley. Berkeley CA, 2005. [19] R. Sindhubargavi, M. Yuvasrri Sindhu and R. Saravanan, “Spectrum Sensing using Energy Detection Technique for Cognitive Radio Networks using PCA Technique,” Sastra University, Indian Journal of Science and Technology, vol 7, no. 4, pp. 40–45, April 2014. [20] Robert E. Collin, Foundations for Microwave Engineering, 2ed, Wiley-IEEE Press 2000. [21] G. Galati and P. van Genderen, “History of radar: The need for further analy and disclosure,” 11th European Radar Conference, Rome, pp. 25-28, 2014. [22] M. Guarnieri, “The Early History of Radar [Historical],” in IEEE Industrial Electronics Magazine, vol. 4, no. 3, pp. 36-42, Sept. 2010. [23] V. S. Chernyak and I. Y. Immoreev, “A Brief History of Radar,” in IEEE Aerospace and Electronic Systems Magazine, vol. 24, no. 9, pp. B1-B32, Sept. 2009. [24] Niraj Prasad Bhatta and M. GeethaPriya,“RADAR and its Applications,” International Science Press, IJCTA, 10(03), pp. 1-9, 2017. [25] Tarun Agarwal. “RADAR-Basics, Types & Applications,” Retrieved from https://www.elprocus.com/radar-basics-types-and-applications/. Accessed on April 27, 2018. [26] Lav Varshney. “Radar system components and system design,” Technical report, Syracuse Research Corporation 6225 Running Ridge Road North Syracuse, NY 13212- 2509, November 2002. [27] S. Pisa, E. Pittella and E. Piuzzi, “A survey of radar systems for medical applications,” in IEEE Aerospace and Electronic Systems Magazine, vol. 31, no. 11, pp. 64-81, November 2016. [28] C. M. Alabaster, “Suppression of co-channel interference in high duty ratio pulsed radar receivers,” International Conference on Radar Systems (Radar), Belfast, pp. 1-6, 2017. [29] Ferran Martiacuten; Lei Zhu; Jiasheng Hong; Francisco Medina, "BALANCED POWER DIVIDERS/COMBINERS," in Balanced Microwave Filters, 1, Wiley-IEEE Press, 2018. [30] R. A. Beltran, “High-efficiency and flat-gain Doherty type transmitter using a 180 degree hybrid-combiner,” IEEE MTT-S International Microwave Symposium (IMS), Honololu, HI, pp. 1726-1729, 2017. [31] T. H. Wang and J. H. Chen, “Power recycling using Wilkinson power combiner with pulsewidth modulation,” IEEE International Symposium on Radio-Frequency Integration Technology (RFIT), Seoul, pp. 223-225, 2017. [32] U. H. Gysel, “A New N-Way Power Divider/Combiner Suitable for High-Power Applications,” IEEE-MTT-S International Microwave Symposium, Palo Alton, CA, pp. 116-118, 1975. [33] IDA KLÄPPEVIK, “Analy, Construction and Evaluation of a Radial Power Divider/ Combiner,” Chalmers University of Technology, Department of Microtechnology and Nanoscience, Sweden 2017. [34] K. J. Russel, “Microwave power combining techniques,” IEEE Trans. Microwave Theory and Techs., vol. 27, pp. 472–478, 1979. [35] K. Chang and C. Sun, “Millimeter-wave power-combining techniques,” IEEE Trans. Microwave Theory and Techs., vol. 31, pp. 91–107, 1983. [36] E. J. Wilkinson, “An N-way hybrid power divider,” IRE Trans. Microwave Theory and Techs., vol. 8, pp. 116–118, 1960. [37] R. Faraji-Dana and H. Javadi-Bakhsh, “A Wideband Twenty-Element Microwave Spatial Power Combiner,” Scientia Iranica.Transaction D, Computer Science Engineering, Electrical D, vol. 21, no. 3, pp. 853-860, 2014. [38] P. F. Goldsmith, “Quasioptical systems: gaussian beam quasioptical propagation and applications.” IEEE Press, 1st ed., 1998. [39] Orbitfr. “Radial Power Combiners,” Retrieved from http://www.orbitfr.com/sites/www.orbitfr.com/files/power-combiners bd.pdf. Accessed on March 28, 2018. [40] A. E. Fathy, Sung-Woo Lee and D. Kalokitis, “A simplified design approach for radial power combiners," in IEEE Transactions on Microwave Theory and Techniques, vol. 54, no. 1, pp. 247-255, Jan. 2006. [41] M. Subhedar and G. Birajdar, “Spectrum Sensing Techniques in Cognitive Radio Networks: A Survey.” International Journal of Next-Generation Networks (IJNGN), vol. 3, no. 2, pp. 37–51, June 2011. [42] M. Elsaadany and W. Hamouda, “Antenna Selection for Dual-hop Cognitive Radio Networks: A Multiple-Relay Scenario", IEEE Transactions on Vehicular Technology, vol. 66, no. 8, pp. 6754-6763, Aug. 2017. [43] M. Elsaadany, “Optimal power allocation in cognitive networks using non-orthogonal AF relays," 39th Annual IEEE Conference on Local Computer Networks (LCN), Edmonton, AB, 2014, pp. 410-413. [44] M. Elsaadany and T. Khattab, “Performance analysis of general order selection in decentralized cognitive radio networks," 2014 IEEE Wireless Communications and Networking Conference (WCNC), Istanbul, 2014, pp. 1827-1831. [45] P. Pawełczak, “Cognitive Radio: Ten Years of Experimentation and Development,” IEEE Communications Magazine, vol. 49, no. 3, pp. 90-100, Mar. 2011. [46] I. F. Akyildiz, Won-Yeol Lee, M. C. Vuran, and Sh. Mohanty, “NeXt generation/ dynamic spectrum access/cognitive radio wireless networks: A survey,” Computer Networks, vol. 50, no. 13, pp. 2127-2159, 2006. [47] M. Elsaadany and W. Hamouda, “Performance Analysis of Non-Orthogonal AF Relaying in Cognitive Radio Networks," in IEEE Wireless Communications Letters, vol. 4, no. 4, pp. 373-376, Aug. 2015. [48] I. F. Akyildiz, B. F. Lo, and R. Balakrishnan, “Cooperative spectrum sensing in cognitive radio networks: A survey,” Physical Communication, vol. 4 no. 1 pp. 40-62, 2011. [49] M. Elsaadany and W. Hamouda, “Energy Efficient Design for Non-Orthogonal AF Relaying in Underlay Spectrum Sharing Networks", IEEE International Conference on Communications (ICC), 2016. [50] M. Elsaadany and W. Hamouda, “Enhancing the Performance of Amplify-and-Forward Cognitive Relay Networks: A Multiple-Relay Scenario", IEEE Global Communications Conference (GLOBECOM), 2015. [51] A. Garhwal, and P. P. Bhattacharya “A Survey on Dynamic Spectrum Access Techniques for Cognitive Radio,” International Journal of Next-Generation Networks, vol. 3, no. 4, pp. 15-32, 2012. [52] S. Ziafat, W. Ejaz, and H. Jamal, “Spectrum sensing techniques for cognitive radio networks: Performance analy,” IEEE MTT-S International MicrowaveWorkshop Series on Intelligent Radio for Future Personal Terminals, pp. 1-4, 2011. [53] C. S. Rawat, G. G. Korde, “Comparison between Energy Detection and Cyclostationary Detection for Transmitter Section of Cognitive Radio,” International Journal Of Electrical, Electronics And Data Communication, Vol. 3, no. 12, Dec. 2015. [54] D. Cabric, S. M. Mishra, and R. W. Brodersen, “Implementation issues in spectrum sensing for cognitive radios,” in Proceedings of the 38th Asilomar Conference on Signals, Systems and Computers, vol. 1, pp. 772–776, Nov. 2004. [55] David M. Pozar “Microwave Engineering,” John Wiley & Sons, 3ed, 2005. [56] M. St˘anculescu, L. Iordache, M. Iordache, D. Niculae and V. Bucat˘a, “Using S parameters in wireless power transfer analy,” 10th International Symposium on Advanced Topics in Electrical Engineering (ATEE), Bucharest, pp. 107-112, 2017. [57] Pozar, David. “Microwave Engineering,” 2ed, August 1997. [58] T. Djeddi, M. Elsaadany, S. I. Shams and W. Hamouda, “Compact Ultra-Wideband Printed Bandpass Filter Based on Coupled-Line Resonator Loading,” 17th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM), Watreloo, ON, pp. 1-2, 2018. [59] S. I. Shams and A. A. Kishk, “Printed Texture With Triangle Flat Pins for Bandwidth Enhancement of the Ridge GapWaveguide,” in IEEE Transactions on Microwave Theory and Techniques, vol. 65, no. 6, pp. 2093-2100, June 2017. [60] S. I. Shams and A. A. Kishk, “Wideband Coaxial to Ridge Gap Waveguide Transition,” in IEEE Transactions on Microwave Theory and Techniques, vol. 64, no. 12, pp. 4117-4125, Dec. 2016. [61] S. I. Shams and A. A. Kishk, “Determining the Stopband of a Periodic Bed of Nails From the Dispersion Relation Measurements Prediction,” in IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 7, no. 4, pp. 621-629, April 2017. [62] S. I. Shams and A. A. Kishk, “Double cone ultra wide band unit cell in ridge gap waveguides,” in IEEE Antennas and Propagation Society International Symposium (APSURSI), Memphis, TN, pp. 1768-1769. 2014. [63] S. I. Shams and A. A. Kishk, “Ridge gap waveguide to microstrip line transition with perforated substrate,” USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), Memphis, TN, 2014, pp. 215 215. 2014. [64] Analog Devices. “Envelope and TruPwr RMS Detector,” Retrieved from http://www.analog.com/media/en/technical documentation/data-sheets/ADL5511.pdf. Accessed on January 16, 2018. [65] Analog Devices. “Envelope Threshold Detector/Trigger,” Retrieved from http://www.analog.com/media/en/technical documentation/data-sheets/ADL5910.pdf. Accessed on January 16, 2018. [66] Analog Devices. “Detector with Envelope Threshold Detection,” Retrieved from http://www.analog.com/media/en/technical-documentation/data-sheets/ADL5904.pdf. Accessed on January 16, 2018. [67] ATmel. “8-bit AVR Microcontroller with 4/8/16/32K Bytes In-System Programmable Flash,” Retrieved from https://www.mouser.com/pdfdocs/Gravitech-ATMEGA328- datasheet.pdf. Accessed on May 1, 2018. [68] SparkFun Electronics. “Dual Fill-bridge Driver,” Retrieved from https://www.sparkfun.com/datasheets/Robotics/L298-H-Bridge.pdf. Accessed on May 1, 2018. [69] RF Com. “Waveguide Switches,” Retrieved from http://www.rfcom.co.uk/upfiles/sivwaveguide-switches.pdf. Accessed on March 1, 2018. [70] Advanced Switch Technology. “Switches,” Retrieved from https://docs.wixstatic.com/ugd/397bbf3132dd99ea0d483890b8bab63993b10e.pdf. Accessed on March 3, 2018. [71] H. Urkowitz,“Energy detection of unknown deterministic signals,” Proc. IEEE, vol. 55, pp. 523–531, April 1967. [72] C. E. Shannon, “Communication in the presence of noise,” Proc. IRE, vol. 37, pp. 10–21, January 1949. [73] Davenport, Wilbur B., and William L. Root. Random Signals and Noise. New York: McGraw-Hill, 1958. [74] M. Zelen and N. C. Severo, “Probability functions,” in Handbook of Mathematical Functions, M. Abramovitz and J. A. Stegun, Eds., NBS Applied Math. Series 55. Washington, DC: U. S. Government Printing Office, vol. 55, 1964. [75] R. A. Fisher and F. Yates, Statistical Tables for Biological, Agriculture, and Medical Research. Edinburgh, U.K.: Oliver and Boyd, 1938. [76] A. Hald, Statistical Tables and Formulas. New York: Wiley, 1952. [77] P. B. Patnaik, “The noncentral x2 and F distributions and their applications,” Biometrika, vol. 36, pp. 202-232, 1949. [78] E. Fix, “Tables of Noncentral x2,” Publications in Statistics. Berkeley, CaIif.: University of California Press, vol. 1, no. 2, pp. 15 19, 1949. [79] F. F. Digham et al., “On the Energy Detection of Unknown Signals over Fading Channels,” in Proceedings of the IEEE International Conference on Communication, Seattle, Washington, USA, pp. 3575-3579, 2003. [80] I. S. Gradshteyn and I. M. Ryzhik, Table of Integrals, Series, and Products. San Diego, CA: Academic Press, sixth ed., 2000. [81] J. G. Proakis, Digital Communications. McGraw-Hill, fourth ed., 2001. [82] A. H. Nuttall, “Some integrals involving the QM-function,” Naval Underwater Systems Center (NUSC) technical report, May 1974. [83] H. V. Trees, Detection, Estimation, and Modulation Theory. New York, NY: John Wiley & Sons, 1968. [84] V. I. Kostylev, “Energy detection of a signal with random amplitude,” in Proc. IEEE Int. Conf. on Commun. (ICC’02), New York City, New York, pp. 1606–1610, May 2002.