System and method for selecting a communication band
View Patent ↗A system and method for making a band selection in a wireless communications device is provided. The available bands include a first-communication band, a second communication band, and an auxiliary band. A wideband diplexer provides a wideband path, which includes the first-communication band and the auxiliary band, and a second-communication band path. A combination duplexer couples to the wideband path, and has an auxiliary signal port, a first-band receive port, and a first-band transmit port. A standard duplexer couples to the second communication path to provide a second-band receive port and a second-band transmit port. In one example, the first communication band is the PCS band, the second communication band is the cellular band, and the auxiliary signal is a GPS satellite signal.
1. A combination duplexer, comprising:
an antenna port configured to 1) receive an auxiliary band signal, 2) receive a receive signal in a communication band, and 3) send a transmit signal in the communication band;
an auxiliary port constructed to provide a signal indicative of the auxiliary band signal;
a receive port constructed to provide a signal indicative of the receive signal;
a transmit port constructed to receive a signal indicative of the transmit signal;
an auxiliary filter between the antenna port and the auxiliary port;
a receive filter between the antenna port and the receive port; and
a transmit filter between the antenna port and the transmit port,
wherein the filters are constructed using a ceramic monoblock,
wherein each filter comprises integral resonators, and the GPS filter resonators are between the receiver filter resonators and the transmit filter resonators.
2. The combination duplexer of claim 1 , further including a tuning component coupled to the auxiliary filter, the receive filter, or the transmit filter.
3. The combination duplexer of claim 1 , further including a tuning component coupled to one of the filters and another tuning component coupled to one of the other filters.
4. The combination duplexer of claim 1 , wherein the receive filter resonators and the transmit filter resonators are spaced farther apart than in a standard ceramic monoblock duplexer.
5. The combination duplexer of claim 1 , wherein the filters are constructed using a multi-layer ceramic device.
6. The combination duplexer of claim 5 wherein the filters are each a SAW filter.
7. The combination duplexer of claim 5 wherein the filters are each a FBAR filter.
8. The combination duplexer of claim 1 , further including control circuitry coupled to the auxiliary port and constructed to generate a control signal.
9. The combination duplexer of claim 8 , wherein a filter is constructed as a frequency agile filter, and the control signal causes the filter to have a different frequency response.
10. The combination duplexer of claim 8 , wherein the receive filter is constructed as a frequency agile filter, and the control signal causes the receive filter to have a different frequency response so that the receive filter passes signals in a different communication band.
11. The combination duplexer of claim 8 , wherein the transmit filter is constructed as a frequency agile filter, and the control signal causes the transmit filter to have a different frequency response so that the transmit filter passes signals in a different communication band.
12. The combination duplexer of claim 8 , wherein the auxiliary filter is constructed as a frequency agile filter, and the control signal causes the auxiliary filter to have a different frequency response so that the auxiliary filter passes signals in a different auxiliary band.