Branching filter package
View Patent ↗A branching filter package has a SAW filter chip housing area which houses a piezo electric base, on which a transmitting SAW filter and a receiving SAW filter having a different frequency passing band with each other, are formed, and an impedance matching circuit and a branching circuit for the transmitting SAW filter and the receiving SAW filter.
1. The surface acoustic wave duplexer comprising:
a transmitting SAW filter having transmitting input and output portions;
a receiving SAW filter having receiving input and output portions; and
a single piezoelectric substrate on which the transmitting and receiving SAW filters are arranged,
wherein a first direction from the transmitting input portion toward the transmitting output portion is different than a second direction from the receiving output portion toward the receiving input portion,
wherein the transmitting and receiving SAW filters are arranged in series in an arranging direction on the single piezoelectric substrate,
wherein the first and second directions are substantially parallel to an orthogonal direction which is orthogonal to the arranging direction.
2. The surface acoustic wave duplexer according to claim 1 , wherein the first direction is opposite to the second direction.
3. The surface acoustic wave duplexer according to claim 1 , wherein each of the transmitting SAW filter and the receiving SAW filter comprises a plurality of series-arm SAW resonators and a plurality of parallel-arm SAW resonators.
4. The surface acoustic wave duplexer according to claim 3 , wherein the output portion of the transmitting SAW filter is electrically connected to the input portion of the receiving SAW filter outside the single piezoelectric substrate.
5. The surface acoustic wave duplexer according to claim 1 , wherein the transmitting SAW filter comprises a plurality of first SAW resonators connected to a ground and wherein the receiving SAW filter comprises a plurality of second SAW resonators connected to the ground.
6. The surface acoustic wave duplexer according to claim 1 , wherein the surface acoustic wave duplexer has characteristic impedance between the approximately 40 ohms and approximately 50 ohms.
7. A surface acoustic wave duplexer comprising:
a transmitting SAW filter having transmitting input and output portions;
a receiving SAW filter having receiving input and output portions; and
a single piezoclectric substrate on which the transmitting and receiving SAW filters are arranged,
wherein the transmitting and receiving SAW filters are arranged in series in an arranging direction on the single piezoelectric substrate,
wherein a first direction from the transmitting input portion toward the transmitting output portion is different than a second direction from the receiving output portion toward the receiving input portion,
wherein at least one of the first and second directions intersects with the arranging direction, and
wherein the first direction is opposite to the second direction.
8. A surface acoustic wave (SAW) duplexer comprising:
a transmitting SAW filter having transmitting input and output portions;
a receiving SAW filter having receiving input and output portions; and
a single piezoelectric substrate on which the transmitting and receiving SAW filters are arranged,
wherein the transmitting and receiving SAW filters are arranged in series in an arranging direction on the single piezoelectric substrate,
wherein a first direction from the transmitting input portion toward the transmitting output portion is different than a second direction from the receiving output portion toward the receiving input portion,
wherein at least one of the first and second directions intersects with the arranging direction, and
wherein the transmitting and receiving SAW filters are formed on the single piezoelectric substrate in an arranging direction so that the first and second directions are substantially parallel to an orthogonal direction which is orthogonal to the arranging direction.