JPH09232789A - Portable high-frequency device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light-weight and thin portable high-frequency device. SOLUTION: This device is provided with a metallic frame 1 with the opened upper and lower parts and a printed board 3, which is mounted in this frame 1 and at the same time, is mounted with an electronic component 2. The opened upper part 7 of the above frame 1 is covered with a metallic cover 8 and at the same time, the board 3, which is mounted in the vicinity of the opened lower part 7a of the frame 1, is provided facing its rear the outside and with this rear covered with an earth pattern 9, the board 3 is electrically connected with the frame 1. Accordingly, a lightening of a portable high-frequency device and a reduction in the thickness of the device are contrived.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable high frequency device.

[0002]

2. Description of the Related Art Conventionally, a portable high-frequency device of this type has a metal frame having upper and lower openings, a printed circuit board mounted in the frame and having electronic components mounted thereon, and an upper opening of the frame. The lower part and the lower opening were each made up of a metal cover. The metal cover is attached above and below the metal frame to prevent unnecessary radio waves inside the high frequency device from leaking out and unnecessary radio waves from entering the high frequency device. Was completely shielded. On the other hand, in such a portable high frequency device, weight reduction and size reduction are important.

[0003]

However, in such a conventional structure, since metal covers are mounted above and below the metal frame, there is a limit to weight reduction and thickness reduction. was there.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a portable high-frequency device which is light and thin.

[0005]

In order to achieve this object, the upper opening of the frame of the portable high-frequency device of the present invention is covered with a metal cover, and the printed circuit board mounted near the lower opening is The back surface is outside, and the back surface is covered with an earth pattern and electrically connected to the frame. Further, this makes it possible to realize weight reduction and thickness reduction.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises a metal frame having upper and lower openings, and a printed circuit board mounted in the frame and having electronic components mounted thereon. The upper opening of the frame is covered with a metal cover, and the printed circuit board mounted in the vicinity of the lower opening has a back surface outside, and the back surface is covered with an earth pattern and electrically connected to the frame. In this portable high frequency device, the portable high frequency device is completely shielded by the ground pattern, the frame and the upper cover formed on the back surface of the printed circuit board. That is, since the lower cover of the frame is not attached, the weight and the thickness can be reduced accordingly.

The printed circuit board according to the second aspect of the invention is
The portable high-frequency device according to claim 1, wherein the electronic component is mounted only on the front surface, and the high-frequency circuit pattern is laid on the front surface, and the electronic component is not mounted on the back surface of the printed circuit board. The device can be made thin, and no protrusion is formed by an electronic component below the portable high frequency device, which facilitates handling. Further, since the electronic component is mounted only on the surface, soldering is completed by one reflow. Furthermore, since the high-frequency circuit is completely shielded by the ground pattern formed on the back surface of the printed circuit board, the frame, and the upper cover, unnecessary radio waves in the high-frequency circuit leak to the outside and unnecessary radio waves from the outside It does not enter the circuit.

A portable board according to claim 2, wherein a multilayer board is used as the printed board of the invention described in claim 3, and the second layer is a ground pattern and the third layer is a low frequency circuit pattern including a power supply pattern. This is a high-frequency device for use in mobile phones and uses a multi-layer substrate, so that the size of a portable high-frequency device can be reduced. Further, since the high frequency circuit and the low frequency circuit are separated via the ground pattern, a high-performance portable high frequency device which is free from mutual influences can be obtained.

An electrode is formed on the side surface of the printed circuit board according to the fourth aspect of the invention, and the electrode is connected to the ground pattern and is also connected to the frame by soldering via the electrode. In the portable high-frequency device described in (1), since the electrodes are formed on the side surface of the printed circuit board,
The degree of freedom in designing the printed circuit board increases, and the size can be reduced.

A fifth aspect of the present invention is the portable high-frequency device according to the first aspect, wherein the frame is provided with a rib substantially parallel to the opening. The rib can prevent the frame from bending. That is, since the frame is strengthened, the frame can be made thinner, so that the weight can be reduced and the price can be reduced.

According to a sixth aspect of the present invention, there is provided the portable high frequency device according to the first aspect, which has a bent portion in which one of the upper opening and the lower opening of the frame is bent inward. The bent portion can strengthen the frame. That is, since the frame is strengthened, the frame can be made thinner, so that the weight can be reduced and the price can be reduced.

According to a seventh aspect of the present invention, there is provided the portable high frequency device according to the fourth aspect, in which one of the electronic component mounting surface of the printed circuit board and the ground pattern surface is soldered to the frame. By soldering the electronic component mounting surface to the frame, the distance between the lower opening of the frame and the printed circuit board can be reduced, and thus the thickness can be reduced. Moreover, if the frame and the ground pattern surface of the printed circuit board are soldered, a reliable shield by the ground pattern surface can be realized.

The electrode formed on the side surface of the printed circuit board of the present invention according to claim 8 has a concave shape, and a claw formed by cutting and raising from the frame is fitted to this electrode and fixed by soldering. In the portable high-frequency device described in 1, the claw fits into the concave shape of the electrode, so that the printed circuit board can be effectively used without taking up an extra space for coupling with the frame on the printed circuit board. . Also, since the frame and the printed circuit board are connected via the claws,
The stress applied to the frame is not directly transmitted to the printed circuit board and is strong against external impact. In addition, the stress due to the difference in thermal expansion between the frame and the printed circuit board will be alleviated. This is a very important requirement especially for portable high frequency devices used outdoors.

According to a ninth aspect of the present invention, an antenna terminal provided near one short side on a rectangular printed circuit board, an interface connector provided near the other short side, and the printed circuit board on the printed circuit board are provided. A receiving unit provided substantially parallel to one long side, a transmission modulation unit provided substantially parallel to the other long side, and an oscillator arranged between the transmission modulation unit and the receiving unit. The portable high-frequency device according to Item 1. Therefore, since the oscillator does not cross the transmission modulator and the receiver, extra interference is not given. Further, since the transmission modulator and the receiver are separated from each other, mutual interference of signals is small. Furthermore, since the interface connector handling low frequencies and the antenna terminal handling high frequencies are separated, unnecessary interference can be prevented. With such consideration, the partition plate is not required, and the weight and the size can be reduced.

The transmission modulator of the invention described in claim 10 is
A quadrature modulator in which the signal from the interface connector is connected to one input and the oscillator input is connected to the other input, a mixer connected to the output of this quadrature modulator, and the output of this mixer And an image filter connected to the quadrature modulator, and a wiring pattern for transmitting the output signal of the quadrature modulator is arranged so as to be orthogonal to the coil of the resonator constituting the oscillator in an electromagnetic field. Is the balanced high-frequency output, and the output wiring pattern of the quadrature modulator is arranged so as to be orthogonal to the coil of the resonator in an electro-magnetic manner, and thus is output from the oscillator. No carrier is guided to the output of the quadrature modulator. Further, even if induced, the outputs of the quadrature modulators are balanced outputs, so they do not cancel each other out, and do not affect the output of the quadrature modulator. With such consideration, it is not necessary to surround the oscillator with a shield case, which contributes to weight reduction and size reduction.

According to the eleventh aspect of the present invention, there is provided the portable high frequency device according to the tenth aspect, wherein the central axis of the coil is a coil which intersects perpendicularly with a wiring pattern through which an output signal of the quadrature modulator is transmitted. The degree of freedom in designing the printed circuit board increases when the coil is arranged on the printed circuit board.

The invention according to claim 12 is the portable high-frequency device according to claim 9, wherein only the interface connector is provided on the ground pattern side of the printed circuit board, and the portable high-frequency device is mounted on the parent printed circuit board face up. And the wiring to the antenna terminal becomes easier.

According to a thirteenth aspect of the present invention, there is provided a portable high-frequency device according to the ninth aspect, in which the mounting portion is provided on the mounting surface side of the interface connector in the vicinity of the opening portion of the frame. Can be easily installed.

According to a fourteenth aspect of the present invention, there is provided a portable high-frequency device according to the twelfth aspect, wherein the mounting portion is provided on the mounting surface side of the interface connector in the vicinity of the opening portion of the frame. Can be easily installed.

The invention described in claim 15 is the portable high-frequency device according to claim 1 in which a frame and a cover are integrated, and since the frame and the cover are integrated, the number of parts is reduced and the weight is reduced. Can be realized.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a perspective view of the portable high frequency device of the present invention. In FIG. 2, reference numeral 1 is a rectangular metal frame, and both upper and lower parts are open. Then, the printed circuit board 3 on which the electronic component 2 is mounted is mounted therein. Reference numeral 4 is an antenna terminal provided on the printed circuit board 3, and 5 is an interface connector. Reference numeral 6 is a rib provided substantially parallel to the upper opening 7 of the frame 1.

FIG. 1 is a sectional view thereof. In FIG. 1, reference numeral 8 is a metal cover fitted in the upper opening 7 of the frame 1. In this embodiment, both the frame 1 and the cover 8 are made of iron with a material thickness of 0.2 to 0.5 mm. This is because processing is easy and soldering is easy. 3 is a printed circuit board, which is a multilayer board. Reference numeral 9 is a ground pattern provided on the back surface of the printed circuit board 3 and covers almost the entire back surface of the printed circuit board 3. 10 is the surface of the printed circuit board 3,
The electronic component 2 is mounted only on the surface 10. A high frequency circuit pattern is laid on the surface 10 with the strip line as the center. Reference numeral 11 is the second layer, which has a ground pattern on the entire surface. Further, 12 is the third layer, and a low frequency circuit pattern including a power supply circuit is laid. Since the second layer 11 has a ground pattern on the entire surface in this manner, strip lines can be formed on the surface 10 and the high frequency circuit and the low frequency circuit are separated. Reference numeral 13 is an electrode formed on the side surface of the printed circuit board 3, and is formed on the back surface of the ground of the front surface 10, the ground pattern of the second layer 11 and the ground pattern of the low frequency circuit including the power source of the third layer 12. The ground pattern 9 is electrically connected. Then, each ground pattern of the printed circuit board 3 and the frame 1 are connected by solder 14a. In this way, the electronic circuit is shielded by the cover 8, the frame 1 and the ground pattern 9. The distance A between the opening 7a below the frame 1 and the ground pattern 9 on the back surface of the printed circuit board 3 is approximately 0.2 to 0.5 mm. Since this distance A is provided, no external stress is directly applied to the printed circuit board 3 and the printed circuit board 3 is protected from external force.

Further, the solder 14a between the printed circuit board 3 and the frame 1 may be performed on the ground pattern 9 side of the printed circuit board 3. In this case, the dimension A becomes slightly larger, but the connection between the ground pattern 9 and the frame 1 becomes more reliable at high frequencies.

Reference numeral 6 denotes a rib, which prevents the cover 8 from being bent, functions to reliably connect the frame 1 and the cover 8 at high frequencies, and also functions as a stopper to prevent the cover 8 from coming off.

To prevent the frame 1 from bending, a bent portion 14 may be formed in the upper opening 7 of the frame 1 as shown in FIG. The bent portion 14 may be formed on the lower opening 7a side.

FIG. 4 shows another example of the connection between the printed circuit board 3 and the frame 1. As shown in FIG. 4, the claw 15 formed by cutting and raising from the frame 1 may be fitted to the concave electrode 13, and the solder 16 may be filled therein for connection. In this case, the claw 15 has a length of about 3 mm and a width of about 1 mm.
Since it is set to mm, the frame 1 and the printed circuit board 3 are elastically connected, and the stress applied to the frame 1 is not directly transmitted to the printed circuit board 3.
Strong against external shock. In addition, stress due to the difference in thermal expansion between the frame 1 and the printed circuit board 3 is relieved, and solder cracks are less likely to occur. Here, 10a is an earth pattern of the high frequency circuit laid on the surface 10.

FIG. 5 is a circuit layout diagram of the portable high frequency device. In FIG. 5, the antenna terminal 4, the antenna switch 18, and the power amplifier 19 are arranged on one short side 17 side of the rectangular printed board 3. Also,
The interface connector 5 is arranged on the other short side 20 side. The receiver 22 is arranged in parallel with the long side 21 and the transmission modulator 24 is arranged in parallel with the long side 23. An oscillator 25 is arranged between the transmission modulator 24 and the receiver 22. As described above, the portable high-frequency device according to the present embodiment can transmit and receive. What is important here is that the antenna terminal 4 handling high frequencies and the interface connector 5 handling low frequencies are separated as much as possible so as to avoid mutual interference. Similarly, the transmission modulator 24 and the receiver 22
Both should be separated as much as possible to avoid mutual interference. Further, the oscillator 25 is arranged between the transmission modulator 24 and the receiver 22, and is used commonly for transmission and reception. In addition, with such an arrangement, the oscillator 25
The distance from to becomes short, the printed pattern wiring can be efficiently realized, and the size can be reduced.

As shown in FIG. 6, the portable high frequency device comprises a transmission system and a reception system. The configuration of the reception system is an antenna switch 18 to which a signal input from an antenna terminal 4 is connected, and an antenna switch 18. A low noise amplifier 26 to which one terminal of the antenna switch 18 is connected, and a bandpass filter 2 to which the output of the low noise amplifier 26 is connected.
7 and the output of the bandpass filter 27 is connected to one input, and the other input receives the first oscillator 28.
Of the first mixer 29 to which the output of
First intermediate frequency filter 30 to which the outputs of 9 are connected
A second mixer 32 having the output of the first intermediate frequency filter 30 connected to one input and the output of the second oscillator 31 connected to the other input;
The second intermediate frequency filter 33 to which the output of the mixer 32 is connected, and the interface connector 5 to which the output of the second intermediate frequency filter 33 is connected.

On the other hand, the transmission system has a quadrature modulator 34 in which the signal from the interface connector 5 is connected to one input and the output signal of the second oscillator 31 is connected to the other input. A mixer 35 in which the output of the quadrature modulator 34 is connected to one input and the output of the first oscillator 28 is connected to the other input.
The image filter 36 to which the output of the mixer 35 is connected, the amplifier 37 to which the output of the image filter 36 is connected, the power amplifier 19 to which the output of the amplifier 37 is connected, and the power amplifier 19 of the power amplifier 19. The antenna switch 18 has an output connected to the other terminal, and the antenna terminal 4 connected to a common terminal of the antenna switch 18.

What is important here is that the output of the second oscillator 31 does not ride on the output 38 of the quadrature modulator 34 as shown in FIG. When QPSK modulation is performed as in this embodiment, the output of the second oscillator 31 is the quadrature modulator 34.
If the output 38 of the above is used, correct modulation cannot be performed. At least the carrier suppression ratio at the output 38 needs to be 35 dB or more. Therefore, in the present embodiment, the second oscillator 31
The magnetic flux of the coil 39 of the resonator constituting the
Is to be orthogonal to the wiring pattern of the output 38 so as not to be electromagnetically coupled. Moreover, even if the output of the second oscillator 31 leaks, the output 3 of the quadrature modulator 34 is prevented from affecting the output 38 of the quadrature modulator 34.
8 is the balanced output.

Therefore, the coil 39 of the second oscillator 31 is
It is important that the axis of is parallel to the wiring pattern of the output 38. However, even when the coil 39 in which the axis of the coil 39 is perpendicular to the printed circuit board 3 is used, the output of the second oscillator 31 is the output 38 of the quadrature modulator 34.
Is no longer affected by making a balanced output,
The degree of freedom in designing the printed circuit board 3 is increased. By making such consideration, a partition plate that has conventionally strictly shielded the second oscillator 31 becomes unnecessary, and it becomes possible to reduce the weight and size.

FIG. 8 shows the interface connector 5
8 is a view in which only the printed circuit board 3 is attached to the ground pattern side, and FIG. 8A is a perspective view thereof.
(B) is a side view. That is, by mounting the interface connector 5 on the back surface side of the printed circuit board 3, the portable high-frequency device can be mounted face up to the parent printed circuit board 40, and the antenna terminal 4 and the like can be easily mounted and removed.

Reference numeral 41 in FIG. 8 or FIG. 2 is a mounting portion for mounting the portable high frequency device on the parent printed circuit board 40 or the like. Two of these are provided on the diagonal line of the opening 7 extending in the frame 1. It is important to provide this mounting portion on the mounting side of the interface connector 5, so that when the mounting portion is mounted on the parent printed circuit board or the like, the receiving portion 42 on the mating side can be made small, and mounting is easy and lightweight. Can be realized.

In this embodiment, the case in which the frame 1 and the cover 8 form a case has been shown, but the frame 1 and the cover 8 may be integrated.

[0035]

As described above, according to the present invention, it is provided with a metal frame having upper and lower openings, and a printed circuit board mounted in the frame and having electronic components mounted thereon. The upper opening is covered with a metal cover, and the printed circuit board mounted in the vicinity of the lower opening has a back surface outside, and the back surface is covered with an earth pattern and is electrically connected to the frame. The portable high-frequency device can be completely shielded by the ground pattern, the frame and the upper cover formed on the back surface of the printed circuit board. That is, since the lower cover of the frame is not attached, the weight and the thickness can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a portable high frequency device according to an embodiment of the present invention.

FIG. 2 is a perspective view of the portable high frequency device.

FIG. 3 is a sectional view of another example of the portable high frequency device.

FIG. 4 (a) is a perspective view of an essential part of the portable high frequency device, and FIG. 4 (b) is a sectional view of an essential part of the portable high frequency device.

FIG. 5 is a circuit layout diagram of the portable high frequency device.

FIG. 6 is a block diagram of the portable high frequency device.

FIG. 7 is a circuit diagram of a main part of the portable high frequency device.

FIG. 8A is a perspective view of another example of the portable high frequency device. FIG. 8B is a side view of the same.

[Explanation of reference numerals] 1 frame 2 electronic component 3 printed circuit board 7 opening 7a opening 8 cover 9 ground pattern 10 surface

Claims (15)

[Claims] 1. A metal frame having upper and lower openings, and a printed circuit board mounted in the frame and having electronic components mounted thereon. The upper opening of the frame is covered with a metal cover. The portable high frequency device in which the printed circuit board mounted near the lower opening has a back surface outside and is covered with a ground pattern and electrically connected to the frame. 2. The portable high frequency device according to claim 1, wherein the printed circuit board has electronic components mounted only on its surface, and a high frequency circuit pattern is laid on this surface. 3. The portable high frequency device according to claim 2, wherein a multilayer substrate is used as the printed circuit board, and the second layer is a ground pattern and the third layer is a low frequency circuit pattern including a power supply pattern. 4. An electrode is formed on a side surface of the printed circuit board,
The portable high-frequency device according to any one of claims 1 to 3, wherein the electrode is connected to a ground pattern and is also connected to the frame via solder via the electrode. 5. The portable high frequency device according to claim 1, wherein the frame is provided with a rib substantially parallel to the opening. 6. The portable high-frequency device according to claim 1, further comprising a bent portion formed by bending one of the upper opening and the lower opening of the frame inward. 7. The portable high frequency device according to claim 4, wherein either the electronic component mounting surface of the printed circuit board or the ground pattern surface is soldered to the frame. 8. The electrode formed on the side surface of the printed circuit board is formed in a concave shape, and a claw formed by cutting and raising from the frame is fitted to this electrode and fixed by soldering.
The portable high frequency device described in. 9. An antenna terminal provided near one short side of a rectangular printed board, an interface connector provided near the other short side, and substantially parallel to one long side of the printed board. 2. The portable device according to claim 1, further comprising: a receiver provided in the transmitter, a transmission modulator provided substantially parallel to the other long side, and an oscillator arranged between the transmitter modulator and the receiver. High frequency equipment. 10. The transmission modulator is connected to a quadrature modulator in which a signal from an interface connector is connected to one input and an input of an oscillator is connected to the other input, and to an output of the quadrature modulator. A mixer and an image filter to which the mixer output is connected, and a wiring pattern for transmitting the output signal of the quadrature modulator is orthogonal to the coil of the resonator constituting the oscillator in an electromagnetic field. 10. The portable high frequency device according to claim 9, wherein the quadrature modulators are arranged as described above and the outputs of the quadrature modulators are balanced outputs. 11. The portable high frequency device according to claim 10, wherein the central axis of the coil is a coil which intersects perpendicularly with a wiring pattern through which the output signal of the quadrature modulator is transmitted. 12. The portable high frequency device according to claim 9, wherein only the interface connector is provided on the ground pattern side of the printed circuit board. 13. The portable high frequency device according to claim 9, wherein the mounting portion is provided on the mounting surface side of the interface connector and near the opening of the frame. 14. The portable high frequency device according to claim 12, wherein the mounting portion is provided on the mounting surface side of the interface connector and near the opening of the frame. 15. The portable high frequency device according to claim 1, wherein the frame and the cover are integrated.