| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave filter with improved balancing between respective balanced signal terminals 214 and 215 and an communication apparatus. SOLUTION: A filter unit 202 including three interdigital electrode parts 206, 207 and 208 arranged along the surface acoustic wave propagation direction is provided on a piezoelectric substrate 201 so as to provide a balance-to- unbalance conversion function. Respective balanced signal terminals 214 and 215 are connected to electrode fingers of the interdigital electrode part 207 respectively. An unbalanced signal terminal 213 is connected to one electrode finger of each of the interdigital electrode parts 206 and 208. Respective ground terminals 216 and 218 connected to the other electrode fingers of the respective interdigital parts 206 and 208 are electrically isolated from each other on the piezoelectric substrate 201.
|
