Radiation-Enhancement Properties of an X-Band Woodpile EBG and Its Application to a Planar Antenna

<table>Broadside gain of the woodpile-covered patch antenna, <svg height="18.4" id="M123" style="vertical-align:-5.56917pt" version="1.1" viewbox="0 0 27.25 18.4" width="27.25" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,11.4)"><path d="M713 296l-5 -25q-47 -7 -59 -20t-23 -72l-15 -79q-9 -48 -3 -74q-15 -3 -55 -13t-63 -15t-59.5 -10t-70.5 -5q-149 0 -243 80t-94 220q0 169 127.5 276.5t336.5 107.5q91 0 206 -36l-10 -165l-29 -1q1 85 -47.5 126t-146.5 41q-153 0 -243.5 -97t-90.5 -242
q0 -122 68.5 -198.5t188.5 -76.5q121 0 139 75l20 86q13 58 -1.5 70.5t-99.5 20.5l5 26h267z" id="x1D43A"></path></g>
<g transform="matrix(.012,-0,0,-.012,12.375,15.475)"><path d="M169 380l92 53q26 16 49 16q80 0 128.5 -56t48.5 -133q0 -108 -72.5 -180.5t-176.5 -91.5q-38 1 -69 18v-131q0 -57 13 -70t71 -18v-27h-236v27q49 5 61 17t12 61v452q0 48 -9.5 58.5t-56.5 16.5v24q66 11 145 43v-79zM169 346v-270q37 -39 94 -39q63 0 101.5 50
t38.5 134q0 78 -38.5 123t-95.5 45q-45 0 -100 -43z" id="x70"></path></g><g transform="matrix(.012,-0,0,-.012,18.42,15.475)"><path d="M696 437v-26q-37 -5 -50.5 -18.5t-28.5 -55.5q-36 -96 -120 -348h-29l-69.5 178.5l-52.5 132.5l-54.5 -141l-64.5 -170h-28q-71 229 -116 357q-13 39 -25.5 49.5t-48.5 15.5v26h207v-26q-45 -7 -53.5 -17t2.5 -44l74 -232h2l116 314h26q39 -111 120 -318h2q50 156 69 231
q10 38 0.5 48.5t-58.5 17.5v26h180z" id="x77"></path></g>
</svg>, normalized to the broadside gain of the patch alone, <svg height="18.6" id="M124" style="vertical-align:-5.73163pt" version="1.1" viewbox="0 0 20.112499 18.6" width="20.112499" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,11.4)"><path d="M713 296l-5 -25q-47 -7 -59 -20t-23 -72l-15 -79q-9 -48 -3 -74q-15 -3 -55 -13t-63 -15t-59.5 -10t-70.5 -5q-149 0 -243 80t-94 220q0 169 127.5 276.5t336.5 107.5q91 0 206 -36l-10 -165l-29 -1q1 85 -47.5 126t-146.5 41q-153 0 -243.5 -97t-90.5 -242
q0 -122 68.5 -198.5t188.5 -76.5q121 0 139 75l20 86q13 58 -1.5 70.5t-99.5 20.5l5 26h267z" id="x1D43A"></path></g>
<g transform="matrix(.012,-0,0,-.012,12.375,15.475)"><path d="M570 304q0 -108 -87 -199q-40 -42 -94.5 -74t-105.5 -43q-41 0 -65 11l-29 -141q-9 -45 -1.5 -58t45.5 -16l26 -2l-5 -29l-241 -10l4 26q51 10 67.5 24t26.5 60l113 520q-54 -20 -89 -41l-7 26q38 28 105 53l11 49q20 25 77 58l8 -7l-17 -77q39 14 102 14q82 0 119 -36
t37 -108zM482 289q0 114 -113 114q-26 0 -66 -7l-70 -327q12 -14 32 -25t39 -11q59 0 118.5 81.5t59.5 174.5z" id="x1D45D"></path></g>
</svg>, in dB, versus frequency; <svg height="12.4375" id="M125" style="vertical-align:-0.1638pt" version="1.1" viewbox="0 0 8.8999996 12.4375" width="8.8999996" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,12.162)"><path d="M499 88q-41 -46 -83.5 -73t-68.5 -27q-41 0 -19 98l52 225q10 43 8 59.5t-16 16.5q-37 0 -112 -65t-117 -135q-14 -42 -38 -179q-36 -7 -75 -20l-7 8l127 594q8 40 2.5 49t-35.5 9h-35l5 25q36 3 71.5 13t56.5 18t25 8q11 0 3 -38l-88 -417h2q77 102 195 167q44 24 79 24
q61 0 30 -130l-52 -220q-8 -33 4 -33q8 0 31 14.5t43 33.5z" id="x210E"></path></g>
</svg> assumes different values, and the woodpile bars nearest to the ground plane are parallel to the electric field radiated by the patch.</table>

International Journal of Antennas and Propagation

fig17

Figure 17

Figure 17: Radiation-Enhancement Properties of an X-Band Woodpile EBG and Its Application to a Planar Antenna 