THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 15 Feb.; (), 1. http://dx.doi.org/1.5515/kjkiees.15... ISSN 1-3133 (Print)ISSN -X (Online) An Analysis on Harmonic Effects of Wideband Stepped Frequency Radars 전승현 김동규 이창석 이동호 Seung-Hyun JunDong-Kyoo Kim*Chang-Seok LeeDong-Ho Lee 요약 (5 MHz.5 GHz).,. VCO DC. 5 MHz.5 GHz. Abstract Harmonic effects in a wideband stepped frequency radar(5 MHz.5 GHz) have been analyzed. As a result of numerical analysis and simulation, when the second harmonic exists in each frequency, a time-domain result represents an additional object which does not exist but looks to be located at a distance of twice the original object distance. The second harmonics can be removed effectively by low pass filters because there are no other signals between DC and a fundamental signal. In this paper, the harmonic problem can be solved by removing the second harmonics of 5 MHz to.5 GHz wideband fundamental signal with two switches and four low pass filters. Key words: Harmonics, Stepped Frequency Radars, Wideband Systems. 서론 (Radar: Radio Detecting and Ranging).., [1],[]., (GPR: Ground Penetrating Radar) [1][3]. [].,. [5] [1195, ]. (Department of Radio-Wave Engineering, Hanbat National University) *(Electronics and Telecommunications Research Institute) Manuscript received October, 1 ; Revised February 3, 15 ; Accepted February 3, 15. (ID No. 11-7) Corresponding Author: Dong-Ho Lee (e-mail: dhlee@hanbat.ac.kr) c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved.
.5. GHz,. GHz 9. GHz,,. [] 97 MHz, 9 MHz 9 MHz,.,..,.... 고조파영향분석 (Δf) (sweep) ( 1). N N [7]. 5 MHz.5 GHz. 5 MHz 1,3 MHz, 3 1,95 MHz,, MHz,.5 GHz.5 GHz.,,,.,. (1)(3) []. 그림 1. Fig. 1. Frequency vs. time sweep diagram of the stepped frequency system. () (3). [9].,.,, LO(Local Oscillator),. ()(9). (1) () 5
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol., no., Feb. 15. 그림. Fig.. Configuration of the stepped frequency radar system. (5) 표 1. Table 1. Baseband signal combination of the receiver. Rx LO ( 1) Rx LO ( 1) Rx LO ( ) Rx LO ( ) Rx LO ( 17) Rx LO ( 19) Rx LO ( 1) Rx LO ( 3) () (7) (13) (1) () (9) (1) (15).,, (1), (13). (m =1,, ). (1) (11) (1) (15) 1. LO, LO, (1), (17), (1) (17),,. (1) (17) LO, LO
, (1), (19), (1) (19),,., LO. (1) (19),. LO LO, () (3).,, (1), (3),,.. () (1) ().. 시뮬레이션 Keysight Advanced Design System(ADS) (harmonic balance). ADS (ts). 3..5 ns, db. dbm,.,,. 1 MHz, 5 MHz.5 GHz. unambiguous range [1] ( ()),. 1 ns. 5 MHz ns.,. [11]. 주파수간격 () dbm, 1 dbm (3),.,,,., LO 그림 3. Fig. 3. Simulation blockdiagram. 7
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol., no., Feb. 15. Amplitude (V) - - 5 1 15 그림..5 ns ( - : dbm, : 1 dbm, : db) Fig.. The time domain result when the transmitted signal is received in.5 ns(tx signal components-fundamental signal: dbm, nd harmonic: 1 dbm, channel attenuation: db). Amplitude (V) - - 5 1 15 그림 5..5 ns ( - : dbm, : dbm, : db) Fig. 5. The time domain result when the transmitted signal is received in.5 ns(tx signal components-fundamental signal: dbm, nd harmonic: dbm, channel attenuation: db).. (.5 ns) (5 ns). dbm (5 Amplitude (V) - - 5 1 15 그림..5 ns ( - : dbm, : 3 dbm, : db) Fig.. The time domain result when the transmitted signal is received in.5 ns(tx signal components-fundamental signal: dbm, nd harmonic: 3 dbm, channel attenuation: db). Amplitude (V) - - 5 1 15 그림 7..5 ns ( - : dbm, : 1 dbm, 3 : 1 dbm, : db) Fig. 7. The time domain result when the transmitted signal is received in.5 ns(tx signal components-fundamental signal: dbm, nd harmonic: 1 dbm, 3rd harmonic: 1 Bm, channel attenuation: db). ns) 5. 3 db
Amplitude(V) - - 5 1 db attenuation db attenuation 15 그림..5 ns db() db () ( - : dbm, : dbm) Fig.. The time domain result comparison between db (red) and db(black) channel attenuation when the transmitted signal is received in.5 ns(tx signal components-fundamental signal: dbm, nd harmonic: 1 dbm). 그림 9. Fig. 9. Transmitter with the hamonic rejection circuit.. 1 dbm, 3 7,. [1]. dbm, dbm db ( ) db (). db db,.,... 고조파제거회로제작,,. 9. 1 SPT (Hittite HMC3LP3) (Mini-Circuits LFCN ). (Hittite HMC- 311LP3), (Mini-Circuits PAT ). 1, 11. VCO, DC,.. 51,1 MHz 1,1 MHz 그림 1. Fig. 1. Schematic of the hamonic rejection circuit. 9
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol., no., Feb. 15. 1 S1 (db) -1 - -3 - nd harmornic 그림 11. Fig. 11. Photograph of the implemented harmonic rejection circuit., 1,1,15 MHz,15 MHz,,153,35 MHz 3, MHz, 3,35,5 MHz 5,5 MHz, 5,5 MHz. 115 S-(S 1 ). 3 db 1 db. S1 (db) 1-1 - -3 - nd harmornic -5 1 Frequency (GHz) 그림 1. 1,1 MHz S- (S 1 ) Fig. 1. S-parameter(S 1 ) measurement results of 1,1 MHz LPF path. -5 1 Frequency (GHz) 그림 13.,15 MHz S- (S 1 ) Fig. 13. S-parameter(S 1 ) measurement results of,15 MHz LPF path. S1 (db) 1-1 - -3 - nd harmornic -5 1 Frequency (GHz) 그림 1. 3, MHz S- (S 1 ) Fig. 1. S-parameter (S 1 ) measurement results of 3, MHz LPF path.. 결론.,,.. 1
S1 (db) 1-1 - -3 - nd harmornic -5 1 Frequency (GHz) 그림 15. 5,5 MHz S- (S 1 ) Fig. 15. S-parameter(S 1 ) measurement results of 5,5 MHz LPF path.,. DC..,,,. References [1] H. M. Jol, Ground Penetrating Radar: Theory and Applications, Elsevier, pp. 73-97, 1. [] A. S. Turk, A. K. Hocaoglu, and A. A. Vertiy, Subsurface Sensing, Wiley, pp. -3, 11. [3] G. Farquharson, "Design and implementation of a to 1, MHz, stepped frequency, ground penetrating radar transceiver", M. S. Thesis, University of Cape Town, Rondebosch, South Africa, 1999. [] M. Jankiraman, Design of Multi-Frequency CW Radars, Scitech Publishing, pp. 135-1, 7. [5] S. -E. Hamran, K. Langley, "A 5.3 GHz step-frequency GPR for glacier surface characterisation", Proc. Int. Conf. on Ground Penetrating Radar, Delft, Netherlands, pp. 71-7, Jun.. [] A. Langman, S. P. Dimaio, B. E. Burns, and M. R. Inggs, "Development of a low cost SFCW ground penetrating radar", Proc. Int. Geosci. Remote Sens. Symp., Lincoln, NE, United States, pp. -, May 199. [7] M. J. Øyan, S. -E. Hamran, L. Hanssen, T. Berger, and D. Plettemeier, "Ultrawideband gated step frequency ground-penetrating radar", IEEE Trans. Geosci. Remote Sens., vol. 5, no. 1, pp. 1-, Jan. 1. [] A. V. Oppenheim, A. S. Willsky, Signals and Systems, (), pp. 39-395, 1999. [9] A. J. Wilkinson, R. T. Lord, and M. R. Inggs, "Steppedfrequency processing by reconstruction of target reflectivity spectrum", Proc. 199 South African Symp. on Communication and Signal Processing, Rondebosch, South Africa, pp. 11-1, Sep. 199. [1] J. D. Taylor, Ultra-wideband Radar Technology, CRC, pp. 33-3,. [11] M. Sato, K. Yoshida, "Bistatic UWB radar system", Proc. IEEE Int. Conf. Ultra-Wideband, Singapore, pp. -5, Sep. 7. [1] M. I. Skolnik, Introduction to Radar Systems, nd Edition, (), pp. 3-5,. 11
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol., no., Feb. 15. 13 : ( ) 13 9: [ 주관심분야 ], RF 19 : ( ) 19 : () 199 : () 19 199 3: 199 : [ 주관심분야 ] 5 : () 5 9: [ 주관심분야 ],,, Embedded WiFi Bluetooth : () : () 7 : () 79: Georgia Institute of Technology, Research Engineer 91: Skyworks Solutions, Inc., Senior Engineer 1: [ 주관심분야 ] RF IC,, 1