High frequency circuit, high frequency component and communication device
An inventive high frequency circuit includes a switch circuit (SPDT 1 ), connected to an antenna terminal (Ant 1 ), using a field-effect transistor for switching between a connection with first to third transmitting terminals (Tx 1 - 1 , Tx 2 - 1 , Tx 3 - 1 ) and a connection with first to third receiving terminals (Rx 1 - 1 , Rx 2 - 1 , Rx 3 - 1 ); a transmitting-side triplexer (Trip 1 ) for branching a transmitting path connected to the switch circuit into transmitting paths of first to third frequency bands; and a receiving-side triplexer (Trip 2 ) for branching a receiving path connected to the switch circuit into receiving paths of the first to third frequency bands. The switch circuit can be formed as an IC to downsize the circuit. For example, in constructing the high frequency circuit with a laminated module using a ceramic laminated substrate or the like, particularly when the number of triplexers occupying a large space is large, the switch circuit is formed as an IC and mounted on the laminated body, whereby the whole structure can be downsized.
1. A high frequency circuit used in a communication device that performs radio communication using at least a first frequency band, a second frequency band higher than the first frequency band, and a third frequency band higher than the second frequency band, the high frequency circuit comprising:
an antenna terminal to be connected to an antenna, a first transmitting terminal for inputting a transmit signal of the first frequency band, a second transmitting terminal for inputting a transmit signal of the second frequency band, and a third transmitting terminal for inputting a transmit signal of the third frequency band;
a first receiving terminal for outputting a received signal of the first frequency band, a second receiving terminal for outputting a received signal of the second frequency band, and a third receiving terminal for outputting a received signal of the third frequency band;
a switch circuit, connected to the antenna terminal, using a field-effect transistor for switching between a connection with the first, second and third transmitting terminals and a connection with the first, second and third receiving terminals;
a transmitting-side triplexer for branching a transmitting path connected to the switch circuit into transmitting paths of the first, second and third frequency bands; and
a receiving-side triplexer for branching a receiving path connected to the switch circuit into receiving paths of the first, second and third frequency bands;
wherein at least one of the transmitting side triplexer and the receiving-side triplexer includes:
a first band-pass filter unit, disposed in a first path between a common terminal and a first branching terminal, and permitting passing of a signal of the first frequency band,
a second band-pass filter unit, disposed in a second path between the common terminal and a second branching terminal, and permitting passing of a signal of the second frequency band and
a third band-pass filter unit, disposed in a third path between the common terminal and a third branching terminal, and permitting passing of a signal of the third frequency band,
wherein first, second and third parallel resonant circuits are arranged between the common terminal and the first, second and third band-pass filter units, respectively, and
wherein a phase adjustment circuit is arranged between the band-pass filter unit and the corresponding parallel resonant circuit in at least two of the first, second and third paths.
2. The high frequency circuit according to claim 1 ,
wherein a transmission line acting as the phase adjustment circuit is arranged in the first and second paths, and a high-pass filter acting as the phase adjustment circuit is arranged between the band-pass filter unit and the parallel resonant circuit on the third path.
3. The high frequency circuit according to claim 1 , wherein a detection circuit is arranged between the transmitting-side triplexer and the switch circuit.
4. The high frequency circuit according to claim 1 , wherein a first low-noise amplifier circuit is arranged between the receiving-side triplexer and the switch circuit.
5. A high frequency component including a high frequency circuit according to claim 1 ,
wherein the high frequency circuit is constructed using an integral laminate comprising pluralities of dielectric ceramic layers provided with pattern electrodes and elements mounted on a surface of the integral laminate.
6. The high frequency component according to claim 5 , wherein the transmitting-side triplexer and the receiving-side triplexer are formed in the integral laminate,
wherein the band-pass filter units are arranged so as not to overlap each other as seen from a lamination direction of the integral laminate.
7. A high frequency circuit system comprising a first high frequency circuit according to the high frequency circuit of claim 1 acting as a first high frequency sub-circuit, wherein the receiving-side triplexer is a first receiving-side triplexer, the antenna is a first antenna, and the antenna terminal is a first antenna terminal, and wherein the high frequency circuit system further comprises a second high frequency circuit acting as a second high frequency sub-circuit including:
a second antenna terminal to be connected to another a second antenna;
a fourth receiving terminal for outputting a received signal of the first frequency band; a fifth receiving terminal for outputting a received signal of the second frequency band; a sixth receiving terminal for outputting a received signal of the third frequency band;
and
a second receiving-side triplexer for branching a receiving path connected to the second antenna terminal into receiving paths of the first, second and third frequency bands.
8. The high frequency circuit system according to claim 7 , wherein a communication system using the first frequency band is wireless LAN or WiMAX, the communication system using the second frequency band is WiMAX, and the communication system using the third frequency band is wireless LAN or WiMAX.
9. A high frequency component comprising a high frequency circuit according to claim 8 , wherein the high frequency circuit is constructed using an integral laminate comprising pluralities of dielectric ceramic layers provided with pattern electrodes and elements mounted on a surface of the integral laminate,
wherein the transmitting-side triplexer, the first receiving-side triplexer, and the second receiving-side triplexer are formed in the integral laminate,
wherein the transmitting-side triplexer, the first receiving-side triplexer, and the second receiving-side triplexer each include a band-pass filter unit which permits passing of a signal of the first frequency band, a band-pass filter unit which permits passing of a signal of the second
frequency band and a band-pass filter unit which permits passing of a signal of the third frequency band, and
wherein the band-pass filter units are arranged so that the wireless LAN band-pass filter unit of the transmitting-side triplexer and the WiMAX band-pass filter unit of the receiving-side triplexer are not brought into closest proximity to each other in a positional relation of the band-pass filter unit as seen from a lamination direction of the integral laminate, and the WiMAX band-pass filter unit of the transmitting-side triplexer and the wireless LAN band-pass filter unit of the receiving-side triplexer are not brought into closest proximity to each other in the positional relation of the band-pass filter unit as seen from the lamination direction of the integral laminate.
10. A communication device using a high frequency component according to claim 5 .
11. A high frequency circuit used in a communication device that performs radio communication using at least a first frequency band, a second frequency band higher than the first frequency band, and a third frequency band higher than the second frequency band, the high frequency circuit comprising:
an antenna terminal to be connected to an antenna, a first transmitting terminal for inputting a transmit signal of the first frequency band, a second transmitting terminal for inputting a transmit signal of the second frequency band, and a third transmitting terminal for inputting a transmit signal of the third frequency band;
a first receiving terminal for outputting a received signal of the first frequency band, a second receiving terminal for outputting a received signal of the second frequency band, and a third receiving terminal for outputting a received signal of the third frequency band;
a triplexer, connected to the antenna terminal, for branching transmitting/receiving path connected to the antenna terminal into transmitting/receiving paths of the first, seconds and third frequency bands;
a first switch circuit using a field-effect transistor for switching between a connection of the transmitting/receiving path of the first frequency band with the first transmitting terminal and a connection of the transmitting/receiving path of the first frequency band with the first receiving terminal;
a second switch circuit using a field-effect transistor for switching between a connection of the transmitting/receiving path of the second frequency band with the second transmitting terminal and a connection of the transmitting/receiving path of the second frequency band with the second receiving terminal; and
a third switch circuit using a field-effect transistor for switching between a connection of the transmitting/receiving path of the third frequency band with the third transmitting terminal and a connection of the transmitting/receiving path of the third frequency band with the third receiving terminal,
wherein the triplexer includes:
a first band-pass filter unit, disposed in a first path between a common terminal and a first branching terminal, and permitting passing of a signal of the first frequency band;
a second band-pass filter unit, disposed in a second path between the common terminal and a second branching terminal, and permitting passing of a signal of the second frequency band; and
a third band-pass filter unit, disposed in a third path between the common terminal and a third branching terminal, and permitting passing of a signal of the third frequency band,
wherein first, second and third parallel resonant circuits are arranged between the common terminal and the first, second and third band-pass filter units, respectively, and
wherein a phase adjustment circuit is arranged between the corresponding band-pass filter unit and the corresponding parallel resonant circuit on at least two of the first, second and third paths.
12. The high frequency circuit according to claim 11 ,
wherein a transmission line acting as the phase adjustment circuit is arranged in the first and second paths, and a high-pass filter acting as the phase adjustment circuit is arranged between the band-pass filter unit and the parallel resonant circuit in the third path.
13. The high frequency circuit according to claim 11 ,
wherein a first low-noise amplifier circuit is arranged between the first switch circuit and the first receiving terminal, a second low-noise amplifier circuit is arranged between the second switch circuit and the second receiving terminal, and a third low-noise amplifier circuit is arranged between the third switch circuit and the third receiving terminal, wherein a first amplifier circuit is connected to the first transmitting terminal, a second amplifier circuit is connected to the second transmitting terminal, and a third amplifier circuit is connected to the third transmitting terminal,
wherein a first low-pass filter circuit is arranged on an output-terminal side of the second amplifier circuit, and a second low-pass filter circuit is arranged on the output-terminal side of the third amplifier circuit, and
wherein a fourth band-pass filter circuit or a first high-pass filter circuit is arranged between the triplexer and the first switch circuit.
14. The high frequency circuit according to claim 11 , wherein a detection circuit is arranged between the triplexer and the antenna terminal.
15. A high frequency circuit system comprising a first high frequency circuit according to the high frequency circuit of claim 11 acting as a first high frequency sub-circuit wherein the triplexer is a first triplexer, the antenna is a first antenna, and the antenna terminal is a first antenna terminal, wherein the high frequency circuit system further comprises a second high frequency circuit acting as a second high frequency sub-circuit, and wherein the second high frequency sub-circuit includes:
a second antenna terminal to be connected to a second antenna;
a fourth receiving terminal for outputting a received signal of the first frequency band;
a fifth receiving terminal for outputting a received signal of the second frequency band;
a sixth receiving terminal for outputting a received signal of the third frequency band; and
a second triplexer for branching a receiving path connected to the second antenna terminal into receiving paths of the first, second and third frequency bands.
16. A high frequency component including a high frequency circuit according to claim 11 , wherein the high frequency circuit is constructed using an integral laminate comprising pluralities of dielectric ceramic layers provided with pattern electrodes and elements mounted on a surface of the integral laminate.
17. A communication device using a high frequency component according to claim 16 .