Fully Distributed Tunable Bandpass Filter Based on <svg style="vertical-align:-4.49648pt;width:124.775px;" id="M1" height="20.85" version="1.1" viewBox="0 0 124.775 20.85" width="124.775" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.022,-0,0,-.022,.062,15.188)"><path id="x42" d="M372 352v-2q176 -27 176 -159q0 -99 -95 -151q-73 -40 -196 -40h-221v28q65 5 78.5 19t13.5 76v404q0 63 -12 77t-72 18v28h257q102 0 150 -34q26 -18 41 -48.5t15 -65.5q0 -111 -135 -150zM213 362h47q80 0 117.5 32t37.5 96q0 56 -33 92t-100 36q-41 0 -56 -10
q-13 -8 -13 -50v-196zM213 328v-203q0 -54 17 -72.5t66 -18.5q67 1 110.5 37t43.5 110q0 147 -192 147h-45z" /></g><g transform="matrix(.022,-0,0,-.022,13.423,15.188)"><path id="x61" d="M433 39l-85 -51q-27 0 -47 20q-16 16 -24 44q-5 -3 -24 -16.5t-27 -18.5t-23 -13.5t-25 -12t-19 -3.5q-52 0 -86 36.5t-34 85.5q0 71 81 99q128 43 155 65v17q0 54 -23 83.5t-62 29.5q-28 0 -45 -19t-29 -66q-7 -23 -29 -23q-15 0 -29 13t-14 30t31 40q25 19 68.5 40.5
t81.5 29.5q49 0 82 -27q45 -39 45 -123v-185q0 -60 35 -60q18 0 36 11zM275 84v156q-12 -6 -49 -23t-41 -19q-31 -14 -46 -31t-15 -43q0 -35 22.5 -55.5t48.5 -20.5q19 0 42 10.5t38 25.5z" /></g><g transform="matrix(.016,-0,0,-.016,23.288,20.575)"><path id="x1D7CE" d="M476 337q0 -157 -63 -254q-63 -96 -162 -96t-163 96q-64 95 -64 251q0 51 7 99.5t24.5 95.5t43 81.5t65.5 56t89 21.5q75 0 127 -55q96 -97 96 -296zM318 224v225q0 111 -16 161t-53 50t-52 -48.5t-15 -162.5v-225q0 -112 16 -160.5t53 -48.5t52 47.5t15 161.5z" /></g><g transform="matrix(.016,-0,0,-.016,31.133,20.575)"><path id="x2E" d="M113 -12q-24 0 -39.5 16t-15.5 42q0 24 16 40.5t40 16.5t40 -16.5t16 -40.5q0 -26 -16 -42t-41 -16z" /></g><g transform="matrix(.016,-0,0,-.016,34.711,20.575)"><path id="x1D7D3" d="M148 676h322l-45 -127h-276l-22 -81q103 -6 151 -20q82 -23 127.5 -79.5t45.5 -134.5q0 -109 -79 -176q-78 -66 -203 -66q-64 0 -105.5 25.5t-41.5 62.5q0 26 17.5 43.5t43.5 17.5q47 0 100 -46q49 -42 90 -42q42 0 71 29.5t29 74.5q0 51 -36.5 90.5t-105.5 61.5
q-47 14 -180 22z" /></g><g transform="matrix(.022,-0,0,-.022,43.175,15.188)"><path id="x53" d="M409 504l-29 -5q-16 60 -44.5 96t-86.5 36q-54 0 -82.5 -32t-28.5 -77q0 -51 30.5 -82.5t96.5 -65.5l35.5 -18t33 -19.5t33.5 -23.5l27 -25.5t24.5 -32t13.5 -36.5t6 -45q0 -80 -62 -134.5t-160 -54.5q-47 0 -98 15q-22 7 -50 21q-8 23 -27 155l30 7q7 -27 18 -52
t30 -51.5t49 -42.5t67 -16q56 0 88 32.5t32 87.5q0 51 -31.5 82t-98.5 67q-80 44 -110 73q-55 53 -55 124q0 75 56 126.5t150 51.5q53 0 126 -23z" /></g><g transform="matrix(.022,-0,0,-.022,53.688,15.188)"><path id="x72" d="M181 342h2q63 107 121 107q24 0 41 -16t17 -34q0 -34 -32 -49q-17 -7 -26 2q-21 20 -43 20q-20 0 -42 -22t-38 -63v-183q0 -50 12.5 -62t69.5 -16v-26h-230v26q47 5 58 17t11 61v207q0 49 -9 60.5t-53 16.5v23q74 12 141 40v-109z" /></g><g transform="matrix(.016,-0,0,-.016,61.988,20.575)"><use xlink:href="#x1D7CE" /></g><g transform="matrix(.016,-0,0,-.016,69.833,20.575)"><use xlink:href="#x2E" /></g><g transform="matrix(.016,-0,0,-.016,73.411,20.575)"><use xlink:href="#x1D7D3" /></g><g transform="matrix(.022,-0,0,-.022,81.875,15.188)"><path id="x54" d="M592 498l-30 -3q-13 63 -31 89q-13 19 -33.5 25.5t-75.5 6.5h-70v-493q0 -60 16 -75.5t86 -19.5v-28h-286v28q68 4 83.5 19.5t15.5 75.5v493h-62q-60 0 -83 -7t-33 -24q-12 -17 -32 -90h-29q10 116 12 180h20q10 -16 21 -20.5t34 -4.5h395q19 0 28.5 5t21.5 20h21
q2 -89 11 -177z" /></g><g transform="matrix(.022,-0,0,-.022,93.487,15.188)"><path id="x69" d="M135 536q-20 0 -35 15.5t-15 35.5q0 22 15 37t36 15t35.5 -15t14.5 -37q0 -21 -15 -36t-36 -15zM252 0h-220v26q48 5 59 17t11 63v206q0 47 -9 58t-54 18v24q78 12 142 39v-345q0 -51 11.5 -63t59.5 -17v-26z" /></g><g transform="matrix(.022,-0,0,-.022,99.494,15.188)"><path id="x4F" d="M381 665q131 0 226.5 -93t95.5 -239q0 -158 -96 -253t-238 -95q-137 0 -231 95t-94 238q0 142 92.5 244.5t244.5 102.5zM359 629q-89 0 -151 -74.5t-62 -208.5q0 -141 69 -233t175 -92q90 0 150.5 74t60.5 211q0 152 -69 237.5t-173 85.5z" /></g><g transform="matrix(.016,-0,0,-.016,116.238,20.575)"><path id="x1D7D1" d="M58 524l-21 12q80 152 229 152q73 0 119 -41q45 -41 45 -96q0 -40 -21.5 -74.5t-62.5 -52.5q57 -20 89.5 -68.5t32.5 -109.5q0 -110 -86 -185t-214 -75q-69 0 -110.5 24.5t-41.5 65.5q0 26 18.5 43t46.5 17q45 0 96 -57q39 -43 79 -43q45 0 71.5 34t26.5 88q0 75 -49 121
q-25 23 -56 39q-34 17 -97 38v17q69 21 100 53t31 78q0 103 -99 103q-40 0 -69.5 -19t-56.5 -64z" /></g></svg> Thin-Film Slow-Wave Structure

<table>(a) Bilateral interdigital coplanar waveguide slow-wave filter (Fishbone Filter) structure on BST/Alumina substrate. (b) Equivalent network of the 2-pole BPF.</table>

International Journal of Microwave Science and Technology

fig1

Figure 1

Figure 1: Fully Distributed Tunable Bandpass Filter Based on <svg style="vertical-align:-4.49648pt;width:124.775px;" id="M1" height="20.85" version="1.1" viewBox="0 0 124.775 20.85" width="124.775" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.022,-0,0,-.022,.062,15.188)"><path id="x42" d="M372 352v-2q176 -27 176 -159q0 -99 -95 -151q-73 -40 -196 -40h-221v28q65 5 78.5 19t13.5 76v404q0 63 -12 77t-72 18v28h257q102 0 150 -34q26 -18 41 -48.5t15 -65.5q0 -111 -135 -150zM213 362h47q80 0 117.5 32t37.5 96q0 56 -33 92t-100 36q-41 0 -56 -10
q-13 -8 -13 -50v-196zM213 328v-203q0 -54 17 -72.5t66 -18.5q67 1 110.5 37t43.5 110q0 147 -192 147h-45z" /></g><g transform="matrix(.022,-0,0,-.022,13.423,15.188)"><path id="x61" d="M433 39l-85 -51q-27 0 -47 20q-16 16 -24 44q-5 -3 -24 -16.5t-27 -18.5t-23 -13.5t-25 -12t-19 -3.5q-52 0 -86 36.5t-34 85.5q0 71 81 99q128 43 155 65v17q0 54 -23 83.5t-62 29.5q-28 0 -45 -19t-29 -66q-7 -23 -29 -23q-15 0 -29 13t-14 30t31 40q25 19 68.5 40.5
t81.5 29.5q49 0 82 -27q45 -39 45 -123v-185q0 -60 35 -60q18 0 36 11zM275 84v156q-12 -6 -49 -23t-41 -19q-31 -14 -46 -31t-15 -43q0 -35 22.5 -55.5t48.5 -20.5q19 0 42 10.5t38 25.5z" /></g><g transform="matrix(.016,-0,0,-.016,23.288,20.575)"><path id="x1D7CE" d="M476 337q0 -157 -63 -254q-63 -96 -162 -96t-163 96q-64 95 -64 251q0 51 7 99.5t24.5 95.5t43 81.5t65.5 56t89 21.5q75 0 127 -55q96 -97 96 -296zM318 224v225q0 111 -16 161t-53 50t-52 -48.5t-15 -162.5v-225q0 -112 16 -160.5t53 -48.5t52 47.5t15 161.5z" /></g><g transform="matrix(.016,-0,0,-.016,31.133,20.575)"><path id="x2E" d="M113 -12q-24 0 -39.5 16t-15.5 42q0 24 16 40.5t40 16.5t40 -16.5t16 -40.5q0 -26 -16 -42t-41 -16z" /></g><g transform="matrix(.016,-0,0,-.016,34.711,20.575)"><path id="x1D7D3" d="M148 676h322l-45 -127h-276l-22 -81q103 -6 151 -20q82 -23 127.5 -79.5t45.5 -134.5q0 -109 -79 -176q-78 -66 -203 -66q-64 0 -105.5 25.5t-41.5 62.5q0 26 17.5 43.5t43.5 17.5q47 0 100 -46q49 -42 90 -42q42 0 71 29.5t29 74.5q0 51 -36.5 90.5t-105.5 61.5
q-47 14 -180 22z" /></g><g transform="matrix(.022,-0,0,-.022,43.175,15.188)"><path id="x53" d="M409 504l-29 -5q-16 60 -44.5 96t-86.5 36q-54 0 -82.5 -32t-28.5 -77q0 -51 30.5 -82.5t96.5 -65.5l35.5 -18t33 -19.5t33.5 -23.5l27 -25.5t24.5 -32t13.5 -36.5t6 -45q0 -80 -62 -134.5t-160 -54.5q-47 0 -98 15q-22 7 -50 21q-8 23 -27 155l30 7q7 -27 18 -52
t30 -51.5t49 -42.5t67 -16q56 0 88 32.5t32 87.5q0 51 -31.5 82t-98.5 67q-80 44 -110 73q-55 53 -55 124q0 75 56 126.5t150 51.5q53 0 126 -23z" /></g><g transform="matrix(.022,-0,0,-.022,53.688,15.188)"><path id="x72" d="M181 342h2q63 107 121 107q24 0 41 -16t17 -34q0 -34 -32 -49q-17 -7 -26 2q-21 20 -43 20q-20 0 -42 -22t-38 -63v-183q0 -50 12.5 -62t69.5 -16v-26h-230v26q47 5 58 17t11 61v207q0 49 -9 60.5t-53 16.5v23q74 12 141 40v-109z" /></g><g transform="matrix(.016,-0,0,-.016,61.988,20.575)"><use xlink:href="#x1D7CE" /></g><g transform="matrix(.016,-0,0,-.016,69.833,20.575)"><use xlink:href="#x2E" /></g><g transform="matrix(.016,-0,0,-.016,73.411,20.575)"><use xlink:href="#x1D7D3" /></g><g transform="matrix(.022,-0,0,-.022,81.875,15.188)"><path id="x54" d="M592 498l-30 -3q-13 63 -31 89q-13 19 -33.5 25.5t-75.5 6.5h-70v-493q0 -60 16 -75.5t86 -19.5v-28h-286v28q68 4 83.5 19.5t15.5 75.5v493h-62q-60 0 -83 -7t-33 -24q-12 -17 -32 -90h-29q10 116 12 180h20q10 -16 21 -20.5t34 -4.5h395q19 0 28.5 5t21.5 20h21
q2 -89 11 -177z" /></g><g transform="matrix(.022,-0,0,-.022,93.487,15.188)"><path id="x69" d="M135 536q-20 0 -35 15.5t-15 35.5q0 22 15 37t36 15t35.5 -15t14.5 -37q0 -21 -15 -36t-36 -15zM252 0h-220v26q48 5 59 17t11 63v206q0 47 -9 58t-54 18v24q78 12 142 39v-345q0 -51 11.5 -63t59.5 -17v-26z" /></g><g transform="matrix(.022,-0,0,-.022,99.494,15.188)"><path id="x4F" d="M381 665q131 0 226.5 -93t95.5 -239q0 -158 -96 -253t-238 -95q-137 0 -231 95t-94 238q0 142 92.5 244.5t244.5 102.5zM359 629q-89 0 -151 -74.5t-62 -208.5q0 -141 69 -233t175 -92q90 0 150.5 74t60.5 211q0 152 -69 237.5t-173 85.5z" /></g><g transform="matrix(.016,-0,0,-.016,116.238,20.575)"><path id="x1D7D1" d="M58 524l-21 12q80 152 229 152q73 0 119 -41q45 -41 45 -96q0 -40 -21.5 -74.5t-62.5 -52.5q57 -20 89.5 -68.5t32.5 -109.5q0 -110 -86 -185t-214 -75q-69 0 -110.5 24.5t-41.5 65.5q0 26 18.5 43t46.5 17q45 0 96 -57q39 -43 79 -43q45 0 71.5 34t26.5 88q0 75 -49 121
q-25 23 -56 39q-34 17 -97 38v17q69 21 100 53t31 78q0 103 -99 103q-40 0 -69.5 -19t-56.5 -64z" /></g></svg> Thin-Film Slow-Wave Structure 

International Journal of Microwave Science and Technology

Fully Distributed Tunable Bandpass Filter Based on Thin-Film Slow-Wave Structure

Figure 1