JP4731546B2 - Antenna device - Google Patents

Description

  The present invention relates to a highly shielded antenna device suitable for preventing malfunction of a high frequency module.

There is a type in which a slot is provided in a housing to which an antenna is attached, and a high-frequency module such as a transmission / reception module is inserted into the slot so that the antenna device can be used. This is because the high-frequency module, which is a module of active parts that are generally likely to fail, can be inserted into or removed from the slot so that it can be replaced immediately when a part fails. It is.
In this type of antenna device, there is a connector connected to a connector provided in the housing on the back side in the insertion direction of the high-frequency module, and a plate for preventing over-insertion is provided on the near side of the high-frequency module. In such a high-frequency module, generally, when priority is given to the fitting of the connector, a gap is generated between the plate and the housing, and if an external electromagnetic wave enters from this gap, the high-frequency module may malfunction. .

In a printed circuit board mounted with electronic components and electronic circuits that are generally used in communication devices and wireless devices, the electronic components and electronic circuits are placed on the top surface to prevent the electronic components and electronic circuits from being affected by external noise such as electromagnetic waves. A box-shaped electromagnetic shield cover is used that covers the four sides and blocks the intrusion of noise.
This electromagnetic shield cover is provided with a plurality of lead parts for grounding, and this lead part is soldered to a ground conductor provided on the printed circuit board, or the lead part is press-fitted into a connector provided on the printed circuit board, and the electromagnetic shield cover is provided. Is prevented from being affected by noise such as electromagnetic waves.
However, since the lead parts for grounding of the electromagnetic shield cover are provided at a predetermined interval, a gap is generated between the printed circuit board and the electromagnetic shield cover at the interval of this lead part, which is difficult when a sealed shield is required. There is a problem.

  In order to solve this problem, a printed circuit board in which a ground pattern is formed on the peripheral side surface of an electronic component or the like to which a shield is applied, and a conductive mouth-shaped grounding member mounted on the printed circuit board and soldered to the ground pattern, A shield cover that covers the printed circuit board and has a box-shaped member with one open side having a spring-like contact portion that is conductively connected to the mouth-shaped grounding member, and is configured on the printed circuit board. There has been proposed a shield structure that can be electromagnetically shielded by being sealed in all directions with respect to the circuit (see Patent Document 1).

JP 2001-24375 A

In the conventional antenna device, a gap is formed between the plate of the high-frequency module and the housing when the high-frequency module connector is securely fitted. If unnecessary waves circulate from the gap, and unnecessary waves circulate inside the high-frequency module from the high-frequency module body or the high-frequency module connector, the high-frequency module malfunctioned.
In order to prevent this, the shield structure shown in Patent Document 1 may be applied to this type of antenna device. However, Patent Document 1 attaches and detaches the shield cover to the mouth-shaped grounding member provided on the printed circuit board. It is not just an electrical connection through a connector. For this reason, there is no problem that a gap is generated between the shield cover based on the connector fitting and the printed board or the mouth-shaped grounding member, and the gap between the printed board and the shield cover is simply removed from the mouth-shaped grounding member and the shield. It is merely a seal with a spring-like contact portion attached to the cover. Therefore, in patent document 1, the subject with respect to the electromagnetic waves from the clearance gap between the plate and housing | casing of a high frequency module based on a connector fitting cannot be solved.

  The present invention has been made to solve the above-described problems, and in an antenna device in which a high-frequency module can be inserted / removed, a high-frequency module by wraparound of unnecessary waves from a gap between the high-frequency module and the antenna housing The purpose is to eliminate malfunctions.

  The present invention inserts a high-frequency module into a slot provided in a housing and engages the connectors with each other. When inserting the high-frequency module, a plate for preventing over-insertion into the housing-side slot of the high-frequency module is disposed on the high-frequency module. In the antenna device provided in the module, a conductive sheet that conductively connects a gap between the plate of the high-frequency module and the outer surface of the housing is attached to the plate of the high-frequency module.

  The present invention also provides a plate for preventing over-insertion of a high-frequency module into a housing-side slot when the high-frequency module is inserted by inserting the high-frequency module into a slot provided in the housing and fitting the connectors together. In the antenna device provided in the high-frequency module, a plurality of conductive sheets that conductively connect the gap between the plate of the high-frequency module and the outer surface of the housing are attached to the plate of the high-frequency module, and the interval L between the plurality of conductive sheets is L <Λ / 2 (λ is the wavelength of the unwanted wave).

  The present invention also provides a plate for preventing over-insertion of a high-frequency module into a housing-side slot when the high-frequency module is inserted by inserting the high-frequency module into a slot provided in the housing and fitting the connectors together. In the antenna device provided in the high-frequency module, a plurality of conductive leaf springs that conductively connect the gap between the plate of the high-frequency module and the outer surface of the housing are attached to the plate of the high-frequency module, and an interval L between the plurality of conductive leaf springs Is such that L <λ / 2 (λ is the wavelength of the unwanted wave).

  In the antenna device according to the present invention, the gap between the plate of the high-frequency module and the housing is electrically connected by the conductive sheet or the conductive leaf spring, so that the wraparound of unnecessary waves from the gap can be blocked. It is possible to prevent malfunction of the high frequency module.

Embodiment 1 FIG.
Hereinafter, an antenna device according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 is a perspective view of an antenna device according to Embodiment 1 of the present invention. FIG. 1 (a) is a perspective view when a high-frequency module is pulled out from a housing, and FIG. 1 (b) is a housing of the high-frequency module. The perspective view when inserted in is shown. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is an enlarged view of portion B in FIG. 2, and FIG. 4 is a circuit configuration diagram of the antenna device in FIG. FIG. 5 shows an operation explanatory diagram according to Embodiment 1 of the present invention.

1 to 3, the housing 2 to which the antenna 1 is attached is provided with a slot 3 on one side thereof. A high-frequency module 4 in which electronic components and electronic circuits are modularized can be inserted into and removed from the slot 3. A high-frequency module connector 6 that is electrically connected to a housing connector 5 provided in the housing 2 is provided on the back side in the insertion direction of the high-frequency module 4, and on the front side of the high-frequency module 4. A plate 7 for preventing over-insertion into the slot 3 is provided. Note that the high-frequency module 4 is generally a module in which active components that are likely to fail are modularized from the viewpoint of maintenance management.

  Generally, in order to ensure the fitting of the electrical connection between the housing connector 5 and the high frequency module connector 6, the high frequency module connector 6 must enter the fitting surface of the housing connector 5. . On the other hand, the plate 7 is originally intended to be in contact with the outer surface of the housing 2 where the slot 3 is provided. However, if priority is given to the fitting of the connectors 5 and 6, the plate 7 and the housing 2 of the high-frequency module 4 The gap Δd must be a plus tolerance so that it is always greater than 0 mm. This is because, when the gap Δd is a negative tolerance smaller than 0 mm, the plate 7 comes into contact with the housing 2 before the fitting of the high frequency module connector 6 and the fitting of the high frequency module connector 6 becomes uncertain. is there. As a result, a gap Δd is generated between the plate 7 and the housing 2, and unnecessary waves (radio waves radiated from the antenna 1 or external radio waves) circulate from the gap Δd, causing malfunction of the high-frequency module 4. become.

  In order to prevent malfunction of the high-frequency module 4, in Embodiment 1 of the present invention, a plurality of conductive sheets 8 that electrically connect the plate 7 and the housing 2 in the gap Δd are attached to the plate 7. ing. As shown in detail in FIGS. 1 and 2, the conductive sheet 8 is arranged along the longitudinal direction of the slot 3 with an interval L between the upper side and the lower side of the high-frequency module 4. This interval L is set so that L <λ / 2, where λ is the wavelength of the unwanted wave. Depending on the wavelength λ of the unwanted wave, the conductive sheet 8 is also provided along the short direction of the slot 3.

  On the other hand, if the conductive sheet 8 is simply sandwiched between the plate 7 and the housing 2, it may be difficult to reliably contact the outer surface of the housing 2. Therefore, as shown in FIG. 3, in the present invention, the conductive sheet 8 attached to the plate 7 is further brought into contact with the housing 2 by bending the conductive sheet 8 attached to the plate 7 by the spacer (projection) 9 provided on the plate 7. To be able to.

  Next, FIG. 4 which shows the circuit block diagram of the antenna device which mounted the high frequency module is demonstrated. In FIG. 4, the high-frequency module 4 includes a transmission / reception changeover switch 41 that switches the antenna 1 between a transmission side and a reception side, a transmission amplifier 42, and a reception amplifier 43. In this way, the transmission / reception selector switch 41, the transmission amplifier 42, and the reception amplifier 43 can be collectively extracted as the high-frequency module 4 because active components that are generally likely to fail are replaced when they fail. This is because it is configured so that it can be taken out as a module as a whole.

  The housing 2 has a transmission signal input connector 21 connected to the transmission amplifier 42 and a reception signal output connector 22 connected to the reception amplifier 43 via the high frequency module connector 6 and the housing connector 5. And a control / power supply connector 23 for supplying a control signal and power to the transmission / reception changeover switch 41, the transmission amplifier 42, and the reception amplifier 43, respectively. The transmission signal input connector 21, the reception signal output connector 22, and the control / power supply connector 23 are connected to a signal processing circuit and a power source (not shown). These signal processing circuit and power supply may be provided in the case 2, but are provided in a separate case away from the case 2.

First, a general operation of the antenna device will be described. When transmitting from the antenna device, the transmission / reception change-over switch 41 selects the transmission amplifier 42 side and inputs a transmission signal to the transmission signal input connector 21. The transmission signal is amplified by the transmission amplifier 42, passes through the transmission / reception changeover switch 41 having selected the transmission amplifier 42 side, and is radiated from the antenna 1 to the space. On the other hand, when receiving by the antenna device, the transmission / reception changeover switch 41 selects the reception amplifier 43 side. A signal arriving at the antenna device is received by the antenna 1, passes through the transmission / reception selector switch 41 that selects the reception amplifier 43, is amplified by the reception amplifier 43, and is output from the reception signal output connector 22. Here, control signals and power for the transmission / reception change-over switch 41, the transmission amplifier 42, and the reception amplifier 43 are supplied from the control / power supply connector 23.

Next, an operation for preventing the malfunction of the high-frequency module 4 due to the intrusion of unnecessary waves will be described with reference to FIG. FIG. 5 is a schematic view of the antenna device of FIG. 1 as viewed from above, and FIG. 5 (a) shows the interval L between the plurality of conductive sheets 8 as L <λ / 2 (λ FIG. 5B is an illustration when the interval L ′ between the plurality of conductive sheets 8 is L ′ ≧ λ / 2 (λ is the wavelength of the unnecessary wave). FIG.
As shown in FIG. 5A, a plurality of conductive sheets 8 are attached to the plate 7 of the high-frequency module 4, and the interval L is set to L <λ / 2 so as to be in conductive contact with the outer surface of the housing 2. In this way, the width L of the gap Δd between the plate 7 and the housing 2 is the same as the distance L between the conductive sheets 8, and the height d of the gap is the same as the gap Δd (where d <L ). The gap Δd operates in the same manner as a waveguide, and the electric field (indicated by an arrow) has only a component perpendicular to the conductive surface, so the relationship between the cutoff frequency fc and the width L is fc = c / (2L) (C is the speed of light, c≈299.8 × 10 ⁹ [mm / s]). Since radio waves having a frequency lower than the cutoff frequency fc do not propagate, if the wavelength of the unwanted wave is λ, and the relationship between λ and the width L of this gap is L <λ / 2, the unwanted wave is blocked by this gap. The

  On the other hand, as shown in FIG. 5B, a plurality of conductive sheets 8 are attached to the plate 7 of the high-frequency module 4, and the interval L ′ is set to L ′ ≧ λ / 2, and the outer surface of the housing 2 is conductively contacted. Let In this way, the width L ′ of the gap Δd between the plate 7 and the housing 2 is the same as the gap L ′ between the conductive sheets 8, and the height d of the gap is the same as the gap Δd (however, d <L <L ′). In this case, assuming that the wavelength of the unwanted wave is λ, the relationship between λ and the width L ′ of this gap is L ′ ≧ λ / 2, so the unwanted wave passes through this gap and the unwanted wave is not blocked.

  As described above, according to the first embodiment, the gap Δd is formed between the plate 7 and the housing 2 in order to securely fit the high frequency module connector 6 to the connector 5 of the housing 2. Even in such a case, since this gap Δd is electrically connected by the conductive sheet 8, the wraparound of unnecessary waves from the gap Δd can be blocked and the malfunction of the high frequency module 4 can be prevented. Can do.

Embodiment 2. FIG.
Next, an antenna device according to Embodiment 2 of the present invention will be described with reference to the drawings. 6 is a perspective view of an antenna device according to Embodiment 2 of the present invention. FIG. 6 (a) is a perspective view when the high-frequency module is extracted from the housing, and FIG. 6 (b) is a housing of the high-frequency module. The perspective view when inserted in is shown.
In FIG. 6, the conductive sheet 81 is mounted on the plate 7 over the entire circumference of the gap Δd between the plate 7 and the housing 2. In the second embodiment, similarly to the first embodiment, the conductive sheet 81 can be reliably brought into contact with the housing 2 by bending the conductive sheet 81 toward the housing 2 by the spacer (projection) 9 provided on the plate 7. You may do it. Other configurations are the same as those of the first embodiment shown in FIG.

  In Embodiment 1 of the invention described above, the plurality of conductive sheets 8 are mounted between the plate 2 and the housing 3 so that the interval L is L <λ / 2 with respect to the wavelength λ of the unwanted wave. In the second embodiment, a conductive sheet 81 is mounted over the entire circumference between the plate 2 and the casing 3, and the conductive sheet 81 allows a gap Δd between the plate 2 and the casing 3 to be a waveguide. The same effect as in the first embodiment can be obtained.

  In the second embodiment described above, the conductive sheet 81 is mounted on the plate 7 over the entire circumference of the gap Δd between the plate 7 and the housing 2. However, depending on the wavelength λ of the unwanted wave, the plate 7 You may provide only in the upper part side and lower part side. That is, the conductive sheet 81 may be separately disposed on the upper surface and the lower surface of the high-frequency module 4, and the conductive sheet 81 may not be provided on the side surface of the high-frequency module 4.

Embodiment 3 FIG.
Next, an antenna device according to Embodiment 3 of the present invention will be described with reference to the drawings. 7 is a perspective view of an antenna device according to Embodiment 3 of the present invention. FIG. 7 (a) is a perspective view when the high-frequency module is extracted from the housing, and FIG. 7 (b) is a housing of the high-frequency module. The perspective view when inserted in is shown. 8 is a cross-sectional view taken along the line AA in FIG. 7, and FIG. 9 is an enlarged view of a portion B in FIG.
In FIG. 7 to FIG. 9, a plurality of conductive fingers (plate springs) 82 that electrically connect between the plate 7 and the housing 2 are disposed in the gap Δd between the plate 7 and the housing 2. Is attached. As shown in detail in FIGS. 8 and 9, the conductive fingers 82 are arranged at intervals L on the upper side and the lower side of the high-frequency module 4 along the longitudinal direction of the slot 3. This interval L is set so that L <λ / 2, where λ is the wavelength of the unwanted wave.

In the case of the third embodiment, the spacer (projection) 9 that bends the conductive sheets 8 and 81 described in the first or second embodiment to the housing 2 side is unnecessary. Other configurations are the same as those of the first embodiment shown in FIG.
In the first and second embodiments of the present invention, the conductive sheets 8 and 81 are mounted between the plate 7 and the housing 2, but in this third embodiment, the conductive fingers are disposed between the plate 2 and the housing 3. (Plate spring) 83 is mounted, and the conductive finger (plate spring) 82 operates the gap Δd between the plate 2 and the housing 3 in the same manner as the waveguide, and the same effect as in the first embodiment is obtained. can get.

It is a perspective view of the antenna device in Embodiment 1 of this invention. It is AA sectional drawing of FIG. 1 in Embodiment 1 of this invention. It is an enlarged view of the B section of FIG. 2 in Embodiment 1 of this invention. It is a circuit block diagram of the antenna apparatus in Embodiment 1 of this invention. It is explanatory drawing which shows operation | movement of the antenna apparatus in Embodiment 1 of this invention. It is a perspective view of the antenna apparatus in Embodiment 2 of this invention. It is a perspective view of the antenna apparatus in Embodiment 3 of this invention. It is AA sectional drawing of FIG. 7 in Embodiment 3 of this invention. It is an enlarged view of the B section of FIG. 8 in Embodiment 3 of this invention.

Explanation of symbols

1: antenna, 2: housing
3: Slot, 4: High-frequency module,
5: Connector for housing 6: Connector for high frequency module
7: Plate, 8: Conductive sheet,
9: Spacer, 21: Transmission signal input connector,
22: Received signal output connector, 23: Control / power supply connector,
41: Transmission / reception selector switch, 42: Transmitter amplifier,
43: Receiving amplifier 81: Conductive sheet
82: Conductive finger (leaf spring)

Claims (6)

  A plate for preventing over-insertion of the high-frequency module into the housing-side slot when the high-frequency module is inserted by inserting a high-frequency module into a slot provided in the housing and fitting the connectors together. The antenna device according to claim 1, wherein a conductive sheet that conductively connects a gap between the plate of the high-frequency module and the outer surface of the housing is attached to the plate of the high-frequency module.   The antenna device according to claim 1, wherein the conductive sheet is attached to the entire periphery of the plate of the high-frequency module.   The antenna device according to claim 1, wherein the conductive sheet is attached to an upper part and a lower part of the plate of the high-frequency module.   A plate for preventing over-insertion of the high-frequency module into the housing-side slot when the high-frequency module is inserted by inserting a high-frequency module into a slot provided in the housing and fitting the connectors together. A plurality of conductive sheets that conductively connect gaps between the plate of the high-frequency module and the outer surface of the housing are attached to the plate of the high-frequency module, and an interval L between the plurality of conductive sheets. Is an antenna device characterized in that L <λ / 2 (λ is the wavelength of the unwanted wave).   The antenna device according to any one of claims 1 to 4, wherein a spacer for bending the conductive sheet toward the housing is attached to a plate of the high-frequency module.   A plate for preventing over-insertion of the high-frequency module into the housing-side slot when the high-frequency module is inserted by inserting a high-frequency module into a slot provided in the housing and fitting the connectors together. A plurality of conductive leaf springs that conductively connect gaps between the plate of the high-frequency module and the outer surface of the housing are attached to the plate of the high-frequency module; The antenna apparatus characterized in that the interval L is L <λ / 2 (λ is the wavelength of an unnecessary wave).

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