JPH10200310A - Nonreversible circuit element and transmission/reception equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deal with the demand for miniaturization and cost reduction and to suppress the dispersion of characteristics or the increase in insertion loss by forming a coupling electrode for detecting the power of transmission signal on a dielectric substrate forming capacitance for matching to be connected to respective center electrodes. SOLUTION: Near a 1st capacitance electrode C1 on a dielectric substrate 24, a coupling electrode 35 is patterned and this coupling electrode 35 is simultaneously formed from the same material as capacitance electrodes C1-C3. Namely, the coupling electrode 35 is integrally formed on the dielectric substrate 24 as the component of the isolator 12, the coupling electrode 35 and the capacitance electrode C1 for matching at an input port are coupled by electrostatic capacitance and transmission power is detected. Therefore, a coupling circuit can be built in the existing isolator 12, and a circuit configuration by other components can be unnecessitated. As a result, a mounting area can be reduced, the number of parts can be decreased, and the miniaturization and cost reduction of the entire transmission/reception equipment can be dealt with. Besides, the dispersion of characteristics can be canceled and the increase of the insertion loss can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lumped constant type non-reciprocal circuit device and a transmission / reception device using the non-reciprocal circuit device.

[0002]

2. Description of the Related Art Generally, a transmission / reception apparatus employed in mobile communication equipment such as a portable telephone and a car telephone is constructed so that a transmission unit and a reception unit are commonly used via a branch unit of one antenna. In the transmitting unit of the transmitting / receiving device, the gain of the PA (power amplifier) is not constant in the frequency band, but may fluctuate depending on the temperature or the power supply voltage.

For this reason, conventionally, as shown in FIG.
1 through the directional coupler 2 to detect a part of the output voltage
By controlling the gain of the AGC amplifier (gain control amplifier) 4 in accordance with the detected value, the output voltage from the PA 1 is maintained at a constant value. In addition,
5 is an isolator and 6 is an antenna.

However, since the directional coupler has a large component size and is expensive, there is a problem that the circuit device becomes large and the cost increases, and there is a strong demand for miniaturization and low cost. Recruitment on the phone is difficult.

[0005] In order to solve such a problem, there is a type in which a coupling capacitor 7 is added in parallel between the PA 1 and the isolator 5 as shown in FIG. According to this, 1
Miniaturization because only one chip component needs to be added,
Can respond to lower prices.

[0006]

By the way, in the case of the coupling capacitor described above, although it is possible to reduce the size and cost as compared with the directional coupler, it is necessary to secure a mounting area by adding the capacitor. And the number of parts increases. For this reason, in order to cope with further miniaturization and price reduction of a mobile phone, improvement in this point is required.

Further, it is necessary to design the capacitor in consideration of accuracy in determining the capacitance value (degree of coupling and insertion loss), and furthermore, radiation (unnecessary radiation) from the coupling portion.
There is a problem that inconveniences such as the occurrence of insertion loss and an increase in insertion loss due to this, or an increase in insertion loss due to the addition of a mounting pattern and a land of a coupling portion are likely to occur.

The present invention has been made in view of the above circumstances, and provides a non-reciprocal circuit device and a transmission / reception device which can respond to demands for downsizing and price reduction, and can suppress variations in characteristics and an increase in insertion loss. It is intended to be.

[0009]

According to a first aspect of the present invention, there is provided a non-reciprocal circuit device having a characteristic that attenuation is small in a transmission direction of a transmission signal and large in a reverse direction, and is connected to each center electrode. A coupling electrode for detecting the power of the transmission signal is formed on a dielectric substrate on which a matching capacitor is formed.

[0010] According to a second aspect of the present invention, one antenna is shared by the transmitting unit and the receiving unit, an amplifier is provided in the transmitting unit with a non-reciprocal circuit element interposed, and the transmission power of the amplifier is reduced. In the transmitting and receiving apparatus provided with a coupling circuit for detecting, the coupling electrode for detecting the transmission power is formed on a dielectric substrate on which a matching capacitor connected to each center electrode of the non-reciprocal circuit element is formed. And

According to a third aspect of the present invention, in the first aspect, the nonreciprocal circuit element is of a lumped constant type, and the coupling electrode is formed so as to be coupled to a matching capacitor on the input port side of the dielectric substrate. It is characterized by having.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 4 are views for explaining an isolator and a transmission / reception apparatus using the isolator according to the first and second embodiments of the present invention. FIG. 1 is an exploded perspective view of a lumped constant type isolator. 2
Is a perspective view of a dielectric substrate, FIG. 3 is an equivalent circuit diagram of an isolator, and FIG. 4 is a circuit configuration diagram of a transmission / reception device.

The transmitting and receiving apparatus 10 of the present embodiment shares one antenna 11 for a transmitting unit and a receiving unit via a branching unit A. The transmitting unit includes a lumped constant isolator 12 in the branching unit A. PA (power amplifier) 13, AG
A C amplifier (gain control amplifier) 14 is provided, and the basic circuit configuration is substantially the same as the conventional one. The isolator 12 has an extremely small attenuation in the transmission direction of the transmission signal,
It has a characteristic that attenuation is large in the reverse direction. This prevents generation of IM due to reflected waves from the antenna 11 and damage of the PA 13 due to load fluctuation. Note that PAs used in recent mobile phones and the like include GaAs-ICs or GaAs-Fs having a monolithic or hybrid structure.
ET is commonly used.

The transmitting section detects the output power from the PA 13 via a coupler described later, and outputs the detected value to the AGC.
A detector 15 for outputting to the amplifier 14 is provided. This AGC amplifier 14 controls the gain according to the output value from the detector 15. That is, when the output value from the detector 15 decreases, the output value is increased by the reduced amount, whereby the output power from the PA 13 is always kept constant. Note that a semiconductor rectifier (diode) is generally used for the detector 15.

As shown in FIGS. 1 and 2, the isolator 12 mainly includes a permanent magnet 22 and a magnetic assembly 2 in a magnetically closed circuit formed by an upper yoke 20 and a lower yoke 21.
3, a dielectric substrate 24 and an earth plate 25 are provided, and a DC magnetic field Hex is applied to the magnetic assembly 23 by the permanent magnet 22.
Is applied. The ground plate 25 is in contact with the bottom surface of the lower yoke 21, and the ground terminals 25 a, 25 a formed integrally therewith are connected to the opening 21 of the lower yoke 21.
Projecting outward from a.

In the magnetic assembly 23, a disc-shaped fillet 27 is disposed on an earth portion 26d integrally formed with first to third center conductors 26a to 26c. 26c are bent and arranged so as to intersect with each other at an angle of 120 degrees with an insulating sheet (not shown) interposed therebetween. An input terminal 28 and an output terminal 29 are integrally formed on the first and second center conductors 26a and 26b, respectively, and the terminals 28 and 29 protrude outward from the opening 21a.

The dielectric substrate 24 is made of a ceramic substrate, a high-frequency printed circuit board, a ferrite substrate, or the like. A hole 24a is formed in the center of the dielectric substrate 24, and the assembly is placed in the hole 24a. 23 ferrites 27 are inserted and arranged. On the upper surface of the dielectric substrate 24, first to third matching capacitance electrodes C1 to C3 are formed in a pattern, and each of the capacitance electrodes C1 to C3 is formed of a thick film electrode, a thin film electrode, or a metal foil electrode. Things.

The first to third central conductors 26a to 26c are connected to the first to third capacitance electrodes C1 to C3, respectively. In addition, the third capacitor electrode C3 has a terminating resistance film 3
The resistance film 30 is connected to the ground plate 25 via a ground electrode 32 formed on the entire lower surface of the dielectric substrate 24 via a through-hole electrode 31.

A coupling electrode 35 is formed in a pattern near the first capacitance electrode C1 of the dielectric substrate 24. The coupling electrode 35 is formed of the same material as the capacitance electrodes C1 to C3 and formed at the same time. It is. A coupling terminal 36 is connected to the coupling electrode 35.
6 is connected to the detector 15 described above.

The end surface 35a of the coupling electrode 35 and the end surface C1a of the first capacitance electrode C1 are opposed to each other with a predetermined gap and a length of the opposing surface. As a result, the transmission power from the PA 13 is coupled from the input terminal 28 via the first capacitance electrode C1 by electrostatic capacitance, and the coupled output is extracted by the coupling electrode 35.

The degree of coupling is determined by the two electrodes 35,
It may be adjusted by setting the gap of C1 and the length of the facing surface, or by disposing a dielectric on the upper surface of the coupling electrode 35 and changing the position of the dielectric or the size of the dielectric. The coupling degree may be adjusted.

According to the present embodiment, the coupling electrode 35 is integrally formed on the dielectric substrate 24, which is a component of the isolator 12, and the coupling electrode 35 and the matching capacitor electrode C of the input port are formed.
Since the transmission power from the PA 13 is detected by coupling the first isolator 1 with the capacitance, the coupling circuit can be built in the existing isolator 12, and the circuit configuration using separate components can be eliminated. As a result, the mounting area can be reduced and the number of components can be reduced, and the overall size of the transmission / reception device can be reduced and the price can be reduced.

Further, since the coupling output is taken out at the opposing portion of the coupling electrode 35 and the capacitance electrode C14, the conventional precision design of the capacitance value can be eliminated, the dispersion of characteristics can be eliminated, and the occurrence of radiation and the mounting pattern can be reduced. Increase in insertion loss due to the addition of the above can contribute to high performance.

In the above-described embodiment, the case where the coupling degree is set with the coupling electrode 35 and the capacitance electrode C1 facing each other in parallel has been described. However, the present invention is not limited to this. Patterns are possible.

For example, FIG. 5 shows an example in which an interdigital electrode pattern is employed.
0a is formed as a recess, and a projection C1b extending into the recess 40a is formed on the capacitor electrode C1. In this case, a greater degree of coupling than in the above embodiment can be obtained as much as the length of the opposing surfaces can be increased.

FIG. 6 shows that both the coupling electrode 41 for obtaining a high degree of coupling and the coupling electrode 42 for obtaining a low degree of coupling are patterned, and either one of the electrodes 41 and 42 is selected. It is an example.

Further, in the above embodiment, the lumped constant type isolator has been described as an example. However, the present invention is not limited to this, and can be applied to a high frequency component having irreversible characteristics such as a circulator. In this circulator, a coupling electrode may be provided at one or more ports of the dielectric substrate, and the incident power may be detected from each port.

In the above embodiment, the case where the lumped-constant isolator 12 is applied to the transmitting / receiving device 10 sharing one antenna has been described. However, the use of the isolator and circulator of the present invention is not limited to this. The present invention is applicable to all wireless communication devices such as a transmitter / receiver using two antennas or a transmitter including only a transmission circuit.

[0029]

As described above, according to the non-reciprocal circuit device according to the first aspect of the present invention, the coupling electrode for detecting the transmission power is formed on the dielectric substrate on which the matching capacitor is formed. A coupling circuit for stabilizing the transmission power can be incorporated in addition to the original function of the non-reciprocal circuit element without increasing the cost and the cost. In addition, there is an effect that a variation in characteristics and an increase in insertion loss can be avoided to contribute to higher performance.

According to the second aspect of the present invention, since the non-reciprocal circuit device is used in the transmission / reception device, a coupling circuit using separate components can be dispensed with, and there is an effect that the entire device can be reduced in size and cost. In addition, there is an effect that it is possible to prevent an increase in insertion loss and leakage power due to wiring and transmission lines in connection with another component.

According to the third aspect of the present invention, since the coupling electrode is coupled to the matching capacitance on the input port side of the dielectric substrate, the transmission power can be detected by coupling with the electrostatic capacitance, and the conventional capacitance value precision design. Is unnecessary, and there is an effect that variations in characteristics and an increase in insertion loss can be avoided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an isolator constituting a transmitting / receiving device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a dielectric substrate of the isolator.

FIG. 3 is an equivalent circuit diagram of the isolator.

FIG. 4 is a circuit configuration diagram of the transmission / reception device.

FIG. 5 is a perspective view showing a modification of the coupling electrode of the embodiment.

FIG. 6 is a perspective view showing another modification of the coupling electrode of the embodiment.

FIG. 7 is a circuit configuration diagram showing a conventional transmission / reception device.

FIG. 8 is a circuit configuration diagram showing another conventional transmission / reception device.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 transmitting / receiving device 11 antenna 12 lumped constant type isolator (non-reciprocal circuit element) 13 PA (amplifier) 24 dielectric substrate 26 a to 26 c center electrode 35, 40 to 42 coupling electrode C1 to C3 matching capacitance electrode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Kawanami 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Inside Murata Manufacturing Co., Ltd.

Claims (3)

[Claims] An attenuation is small in a transmission direction of a transmission signal,
In a non-reciprocal circuit device having a characteristic that attenuation is large in a reverse direction, a coupling electrode for detecting the power of the transmission signal is formed on a dielectric substrate on which a matching capacitor connected to each center electrode is formed. Irreversible circuit element. 2. An antenna is commonly used by a transmitting unit and a receiving unit, and an amplifier is disposed in the transmitting unit via a non-reciprocal circuit element, and a coupling circuit for detecting a transmission power of the amplifier is provided. The transmission / reception device according to claim 1, wherein a coupling electrode for detecting the transmission power is formed on a dielectric substrate having a matching capacitor connected to each center electrode of the non-reciprocal circuit device. 3. The non-reciprocal circuit device according to claim 1, wherein the non-reciprocal circuit device is of a lumped constant type, and the coupling electrode is formed so as to be coupled to a matching capacitor on the input port side of the dielectric substrate. Irreversible circuit element.