Design of Compact Dual-Band Microstrip Patch Antenna

Design of Compact Dual-Band Microstrip temporary hookup Antenna for GPSK-PCS Operation Ho-yong Kim, Yong-nn Lee, Chung-ho Won, Hong-min Lcc Department of Electronics emailprotected Univerrily hi-Dong, Yeongtong-Cu, Suwon-Si, Kyonggi-do, Korea email emailprotected com lnlraduetion In recent years, with the advance o f technology, the pack for an barbel direct a1 mutibands i s increasing rapidly. Such as GPS and K-PCS, The multi-hand aerials with one feeding pon uptake the multiple resonance technolagyl such overturel be difficult lo provide a good polarization efficiency for GPS signal reception.So the integrated GPSIK-PCS dual-band forward pass using two feeding pan has been proposed in this paper. Referenced dual-band advance using two feeding pon has matched poiariration of integrated system. 2 but it has large surface. Proposed antenna uses miniafurizalion proficiency that is to insect ilits. This technique is to increase elecVlcal surface length by abrasions. 3-5 Op erating frequency o f proposed Bntenna is greatly lowered by slit. Meander line secret plan and squ are ring objet dart with four diu o f proposed antenna are about 70% and 50% ofreferenced antenna size.The proposed antenna composed of a low-profile cylindrical monopole with a top-loaded wind up line blot for K-PCS Operation, and a comer-truncated square-ring microstrip patch antenna with four-slits for GPS ooeration. Pmposed Antenna Design The geometry and design parameter of the proposed antenna for compact GPSIK-PCS deed i s presented in framing I. The proposed antenna has the common ground categoric, but i s fed by erupt feeding pon. The antenns for GPS-hand i s realized by using a corner-truncated square-ring microstrip patch with four slits.The outside side length and inner ride length are40mm(L,)and IZmm(&) p % t i d printed on a rubrtrale o f thickness 1. 6mm(h) and y, relative peminiviry (e, 4. 4). The middle ofthe substrate is removed for inner rectangular d i t area ( b x b ) of patch. Feed position for right circularly polarized (RHCP) wave operation is placed along x-axis. and the distance of the probe feed away fram the patch center i s denoted as 6 . 6 m m ( / ) . The four-rlitr at the comers are of equal length I3. 5mm(S)and width Imm(w). Fig 2(a) shows phoney reNm loss of the proposed anlenna for GPS receiving antenna with various d i t lengths(S).It i s noted that the reSonant frequency rapidly lowered with increasingdesign parameter(S). In f h i way, the excited surface current paths are lengthened in the propoed designs, and the operating frequency is greatly lowered. 0-7803-8302-8/04/$20. 00 IEEE 3529 02004 Also, the shorted meander line patch antenna with low-profile cylindrical monopole top is loaded at the center of square ring patch for K-PCS operation. For brbadband characteristic, cylindrical monopole has a large diameter of 6. 2mm(d,) and l e n h 10. 7mm(h2). The eander line patch has a ride lengh Z l m m ( p ) and i s connected to the common ground by two same shorting posh, which have a diameter of 2. 2mm(d2). By varying ofthe shorting ports diameter(d2), good impedance matching can easily be obtained. Figure 2(b) shows simulated retum loss for the p r a p e d K-PCS antenna with various slit lengthr(m,) of meander line patch. Meander line patch size can be reduced by increasing inserted slit length. Because of the antenna for K-PCS operation interfere the axial mtio of GPS receiving antenna, the miniatufimion of GPS antenna is limited.According to the experiment, the patch size of GPS antenna for circular polarized operation must he over about twice the size of KPCS antenna with meander line suunurc. In the proposed designs, the bandwidth of3-dB axial mtio is about 13 MHz, which is much larger than that required for GPS operation at 1575 MHz. The measured axial ratio ofthe antenna for GPS operation i s presented in Figure 3. Figure 4 shows measured re 101 of proposed antenna. The impedance b andwidths (. lOdB retum larr) are about lZOMH(1744MHr-1864MH)far K-PCS band and 60MHr (IS46MHr-1606MHz) for GPS-band.The isolation between the two feeding pons of the PCS and GPS elemenls is less than -17dB. Measured light beam panems of the proposed antenna at l8OOMHz and ISROMHz are presented in Figure 5 and 6, respectively. The K-PCS antenna radiation panem at IROOMHz shows a monopole radiation panem, 10 this fype of antenna is suitable for applications on a vehicular communication system. For the GPS anfenna at ISROMHz, good broadside band radiation panem is obtained. Far K-PCS operation the measured pea* antenna micturates is about 2. 4dBi and t h c gain changes are within O. JdBi, for GPS operation the measured peak antenna gains is about 7. dBi and the vanations of gain does not exist. finding Proposed antenna has a integrated slmcturc of microitrip patch antenna with two feeds for dual-band oprmtion(GPSiK-PCS). A low-profile cylindrical monopole with a shorted meander l ine patch i s loaded for K-PCS operation, which rhowr a linearly polarized monopole patkm with broadband characterirlic. The radiating tender for GPS operation is a novel square-ring microstip path with truncated comers with four slits, which provide circularly polarized braadrids radiation panemr. size reduction of proposed antenna is achieved by using slits.Meander line patch and square ring patch with four . lib of proposed antenna are about 70% and SO% of referenced antenna sire. As the proposed antenna has a compact size for dual band operation, it will be suitable for practical vehicular mobile communication antenna applications. R&ECe I R. Kronberger, H. Lindenmcier, L. Reiter, J. Hapf, Multi hand planar Invencd-F C r a Antenna for Mobile Phone andGPS,2714p-Z717p,AP confer. 1999 3530 2 I. Y. Wu and K. L. Wong, Two inlegraled stacked shorted patchantennas for DCSiGPS operations, Micra wave Opt. Techno1 . Len. , Vol. 30. July, 2001.I31 S. Reed, L. Desclar, C. Terref, and S. T outain, Patch Antenna sizing Reduction By Means Oflnductive Slots, Micro wave Opt. Teehnol. Len. ,Vol29. Apri, 2001. 1 41 J. Y. Wu and K. L. Wong, Single-feed Square-ring Microstip Antenna wilh lruncated comers for Compact ircularpolarization Operation, Electronics lea. , Vol. 34, May,1998. 5 W. S. Chen, C. K. Wu, and K. L. wong. I fiction Compact Circularly polarized Square Microstrip Antennq IEEE Trans. ,Antennas Propagat. , Vol. 49, March, 2001, L, = 40mm, L, = 12mm, S = 13. 5mm, t = 5. 74mm. IY = I n f = 6. 6. p = Zlmnr, m, =ZOmm, ml =3. mm, d) = 6. 2mm, d* = 2. 2. d, =9. 3mm h, = 1. 6mm. h2 =10. 7mm Fib. 1. Geomelly and dimiiiimi ofthe pmpanrd a n t m i l for CPSIK-PCS operation. (a) The variation against parameter S (b) The variation againsl parmnster m, Fig. 2. Simulated return loss wilh vriour ImgthsiS) nnd vsriour slit lengthsim,). slit 3531 I E 4 , d B -2 1. 560 1. 565 1. 570 1. 575 1. 580 . -15 FrequanollGHz , I . 1. 5 2. 0 r4enwffi 2. 5 Fig. 3. The measured dehydra ted ratio. Fig 1 Measured r t b m loss of antenna. . (a) x-2 plane ) x-Y plane Fig 6. Measured radiation panem for GPS operation f=1580MHz 3532