Wave transmission lines and networks – Plural channel systems – Having branched circuits
Reexamination Certificate
2002-06-14
2004-01-27
Tokar, Michael (Department: 2819)
Wave transmission lines and networks
Plural channel systems
Having branched circuits
C333S134000
Reexamination Certificate
active
06683512
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high frequency module and, more particularly, to a high frequency transmitter module which comprises transmitter power amplifiers, switch circuits, couplers (directional couplers) and a branch filter circuit, and is suitable for a dual band mobile wireless terminal.
2. Description of Related Art
In recent years, dual band mobile phones have been proposed as an alternative to common mobile phones employing a single transceiver system. The dual band mobile phones include two transceiver systems which are selectively employed for signal transmission depending on regionalism and their intended use, and are promising as highly convenient mobile phones.
In European countries, dual band mobile phones have recently been used which employ a plurality of transceiver systems, i.e., a GSM system and a DCS system, having different communication bands.
FIG. 10
is a block diagram illustrating high frequency circuitry of a GSM/DCS dual band mobile phone. The high frequency circuitry comprises a switch module ASM
1
which includes low pass filters, switch circuits and a branch filter circuit for separating two transceiver systems GSM and DCS having different pass bands from each other and switching the respective transceiver systems DCS and GSM between a transmitter side TX and a receiver side RX, a transmitter branch TX and a receiver branch RX for the transceiver system DCS, and a transmitter branch TX and a receiver branch RX for the transceiver system GSM.
The transmitter branches TX for the respective transceiver systems DCS and GSM include couplers COP
100
and COP
200
, and power amplifiers AMP
100
and AMP
200
. The power amplifiers AMP
100
, AMP
200
each include a power amplification circuit MMIC and a matching circuit.
In signal transmission, transmission signals amplified by the power amplifier AMP
100
or AMP
200
on the transmitter side TX pass through the coupler COP
100
or COP
200
and further the high frequency switch module ASM
1
including the low pass filters, the switch circuits and the branch filter circuit, and are at length transmitted as radio frequency signals from an antenna ANT.
On the other hand, the receiver branches RX for the respective transceiver systems DCS and GSM respectively include band pass filters BPF
300
and BPF
400
, and low noise amplifiers AMP
300
and AMP
400
. In signal reception, radio frequency signals received by the antenna ANT are introduced through the high frequency switch module ASM
1
and, after unwanted signals having frequencies close to a reception band are removed from the received signals by the band pass filter BPF
300
or BPF
400
, the resulting signals are amplified by the low noise amplifier AMP
300
or AMP
400
on the receiver side RX.
All the circuits required for construction of the respective transceiver systems should be mounted in the dual band mobile phone. Where components dedicated for the respective transceiver systems are employed for the construction of the circuitry, the size and costs of the dual band mobile phone are increased. Accordingly, there is a need to share common circuit components as much as possible for the size reduction and cost reduction of the mobile phone. Further, there is a need to improve the power application efficiencies of the transmitter power amplifiers which consume most of the power supplied to the mobile phone.
To meet these needs, Japanese Unexamined Patent Publication No. 11-225088 (1999), for example, discloses a multi-band high-frequency switch module ASM
1
for size reduction.
FIG. 11
illustrates the multi-band high-frequency switch module ASM
1
. The multi-band high-frequency switch module ASM
1
comprises a branch filter circuit including two notch circuits for separating two transceiver systems having different pass bands from each other, switch circuits SW for switching the respective transceiver systems between transmitter branches and receiver branches, and low pass filters LPF provided for the respective transmitter branches. In the branch filter circuit, the two notch circuits include LC devices connected in parallel. First terminals of the notch circuits are connected to each other to serve as a common terminal for the two transceiver systems, while second terminals of the notch circuits are connected to the respective switch circuits SW.
Nowadays, components of the high frequency switch in the dual band system are partly integrated into a module, as disclosed in Japanese Unexamined Patent Publication No. 11-225088 (1999), rather than mounted on a printed wiring board. However, this arrangement suffers from a limitation to the size reduction, because all the components of the high frequency switch module and the transmitter power amplifiers are mounted on the printed board.
Where the components of the high frequency switch module and the transmitter power amplifiers are mounted on the printed wiring board, the resulting high frequency circuitry rarely satisfies characteristic requirements for the mobile phone. Therefore, inter-component characteristic adjusting circuits are additionally required thereby to pose a design limitation. The provision of the additional circuits correspondingly increases the size of the mobile phone and reduces the power application efficiencies of the power amplifiers with a correspondingly greater power loss.
Further, couplers are provided for monitoring the outputs of the power amplifiers in some cases. Where the couplers are mounted on the printed wiring board, characteristic adjusting circuits for impedance matching should be provided between the couplers and the power amplifiers and between the couplers and the high frequency switch module. The provision of the additional circuits correspondingly increases the size of the mobile phone and reduces the power application efficiencies of the power amplifiers with a correspondingly greater power loss.
SUMMARY OF THE INVENTION
To solve the aforesaid problems, it is an object of the present invention to provide a high frequency module having advantageous characteristics in which components of circuitry ranging from power amplifiers to a branch filter circuit for separating a plurality of transceiver systems having different pass bands from each other are integrated for size reduction thereof.
In accordance with one aspect of the present invention, there is provided a high frequency module, which comprises: a laminate board having a plurality of dielectric layers stacked one on another; a branch filter circuit for separating a plurality of transceiver systems having different pass bands from each other; switch circuits connected to the branch filter circuit for switching the respective transceiver systems between transmitter branches and receiver branches; and power amplifiers respectively connected to the switch circuits and each comprising a matching circuit and a high frequency amplification semiconductor device for amplifying a transmission signal having a frequency within a pass band of each of the transmitter branches.
In the high frequency module, components of the circuitry ranging from the branch filter circuit to the power amplifiers are integrated for size reduction of the module. Further, the respective components can simultaneously be designed, so that the characteristics of the entire module can optimally be adjusted. Without the need for the provision of inter-component characteristic adjusting circuits, a power loss can be reduced. In addition, the time required for designing a mobile wireless terminal can be reduced for cost reduction.
In accordance with another aspect of the present invention, the high frequency module further comprises couplers provided in the laminate board for monitoring outputs of the power amplifiers.
Where the couplers for monitoring the outputs of the power amplifiers are integrated in the laminate board, the outputs of the power amplifiers can be monitored. Without the need for the provision of the characteristic adjusting circuits for the impedance matching, the si
Isoyama Shinji
Nakamata Katsurou
Okuda Toshio
Shimura Teruyuki
Hogan & Hartson
Kyocera Corporation
Mai Lam T.
Tokar Michael
LandOfFree
High frequency module having a laminate board with a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High frequency module having a laminate board with a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High frequency module having a laminate board with a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3188991