Method facilitating inter-mode handoff
View Patent ↗A cellular handset supports non compressed handover for different frequency ranges, and different wireless standards.
1. A handset supporting difference frequency bands comprising:
an antenna transceiving a signal;
a diplexer connected to the antenna having a first and a second diplexer output;
a first antenna switch, connected to the first diplexer output, having a first and a second output;
a first transmitter for a first frequency band connected to the first output of the first antenna switch;
a first receiver for the first frequency band connected to the second output of the first antenna switch;
a second antenna switch, connected to the second diplexer output, having a first and a second output;
a second transmitter for a second frequency band connected to the first output of the second antenna switch; and
a triplexer, operative to transceive the first, second, and third frequency bands, connected to the second output of the second antenna switch, having a first output connected to a receiver at the second frequency, a second output connected to a receiver at the third frequency band, and a third output connected to a transmitter of the third frequency band.
2. A handset as in claim 1 , wherein the first frequency band is GSM 900.
3. A handset as in claim 1 , wherein the second frequency band is GSM 1800.
4. A handset as in claim 1 , wherein the third frequency band is UMTS.
5. A handset as in claim 1 , further comprising:
the first antenna switch having a third output;
a receiver for the fourth frequency band connected to the third output of the first antenna switch;
the second antenna switch having a third output; and
a receiver for the fifth frequency band connected to the third output of the second antenna switch.
6. A handset as in claim 5 , wherein the fourth frequency band is GSM 850.
7. A handset as in claim 5 , wherein the fifth frequency band is GSM 1900.
8. A handset as in claim 5 , wherein the third frequency band is UTMS.
9. A handset, as in claim 1 , the triplexer including:
a first bandpass filter connecting to the receiver for the second frequency band;
a first transmission line, connected to the first bandpass filter;
a second bandpass filter connecting to the transmitter in the third frequency band;
a second transmission line, connected to the second bandpass filter and first transmission line; and
a third bandpass filter connecting to the receiver in the third frequency band;
wherein transmission lines are chosen to appropriately rotate the reject band impedances to open circuits as required.
10. A handset as in claim 1 , the triplexer including:
a first transmission line;
a first and a second bandpass filter connecting to the first transmission line, wherein the first bandpass filter passes the second frequency band and the second bandpass filter passes the third frequency band;
a second transmission line connecting to the first transmission line; and
a third bandpass filter connecting to the second transmission line, for passing the third frequency band;
wherein the second transmission line is chosen to appropriately rotate the reject band impedance of the third bandpass filter into an open circuit at the passband of filters one and two.
11. A handset comprising:
an antenna transceiving a signal;
an antenna switch, connected to the antenna, having a first, a second, a third, a fourth, and a fifth output;
a first transmitter for first and fourth frequency bands connected to the first output;
a first receiver for the first frequency band connected to the second output;
a second receiver for a fifth frequency band connected to the third output;
a second transmitter for the second and fifth frequency bands connected to the fourth output;
a quadplexer, operative to transceive four frequency bands, connected to the fifth output, having outputs connected to a receiver in the first frequency band, a receiver in the second frequency band, a receiver in the third frequency band, and a transmitter of the third frequency band.