FILTER AND MULTIPLEXER

• Main Authors: TSUKIDATE HITOSHI, KAKITA NAOKI
• Format: Patent
• Language: English; Japanese
• Published: 05.11.2020
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS

To set the frequency temperature coefficient of the high frequency end and the low frequency end of a pass band independently.SOLUTION: A filter includes a support board, an insulating layer that is directly or indirectly bonded onto the support board and has a different average thickness between a first region and a second region, a piezoelectric board that is directly or indirectly bonded to the insulating layer and whose elastic constant temperature coefficient sign is opposite to that of the insulating layer elastic constant temperature coefficient, a series resonator provided on the piezoelectric board in the first region, having a pair of comb-shaped electrodes, and connected in series between a first terminal and a second terminal, and a parallel resonator provided on the piezoelectric board in the second region, having a pair of comb-shaped electrodes, and connected in parallel between the first terminal and the second terminal.SELECTED DRAWING: Figure 6 【課題】通過帯域の高周波端と低周波端との周波数温度係数を独立に設定すること。【解決手段】支持基板と、前記支持基板上に直接または間接的に接合され、第１領域における平均厚さと第２領域における平均厚さとは互いに異なる絶縁層と、前記絶縁層上に直接または間接的に接合され、弾性定数の温度係数の符号が前記絶縁層の弾性定数の温度係数の符号と反対である圧電基板と、前記第１領域における前記圧電基板上に設けられ、一対の櫛型電極を有し、第１端子と第２端子との間に直列に接続された直列共振器と、前記第２領域における前記圧電基板上に設けられ、一対の櫛型電極を有し、前記第１端子と前記第２端子との間に並列に接続された並列共振器と、を備えるフィルタ。【選択図】図６