JP2001223524A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device small in size, high in efficiency and suitable to a mobile device by providing devices and radiating elements integrally mounted in one device. SOLUTION: Two points set in one radiating element are excited by two active devices. In such a case, a circuit is formed so that the distances of signal lines that respectively pass through the two active devices can be difference as much as 1/2 effective wavelength from each other, so that the two points are excited in opposite phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antenna device in which a radiating element and a semiconductor active element are integrated. The present invention has been developed for performing indoor communication or indoor mobile communication between devices using microwaves, but can be widely used for other purposes.

[0002]

2. Description of the Related Art A conventional example of an antenna device in which a radiating element and a semiconductor active element are integrated will be described.
A first example of the conventional device is shown in FIG. FIG.
(A) is a top view of the entire device, and (b) is a detailed view of a single element. This device is based on [J. Birkeland and T. It
oh: A 16 Elements Quasi-optical FET Oscillator Powe
rCombining Array with External Injection Locking,
IEEETrans.on MicrowaveTheory and Techniques, Vol.
40, No. 3, pp. 475-481, March 1992]. In this structure, a pull-in excitation signal (Locking Signal) is supplied from an input terminal 20 constituted by a feed line. The excitation input signal is sequentially branched by the Wilkinson divider 21 and distributed to 16 single elements 23 forming an oscillator. Each single element 23 has one FET (field effect transistor) 22
And a signal appearing at the drain electrode of the FET 22 excites a microstrip antenna element that resonates with the open stub 24. In the device having this structure, high-frequency powers transmitted by a plurality of (16) elements are combined in space, and the power shared by the individual elements can be reduced. FIG.
The portion indicated by the broken line in (a) is the ground conductor portion on the back surface.

FIG. 6 shows a second example of a conventional apparatus. FIG. 6A is a perspective view showing the structure of the entire apparatus, and FIG. 6B is a sectional structural view of the apparatus. This device is [K.Kamo
gawa, T.Tokumitsu, M.Akikawa: A Novel Microstrip Ante
nna Using Alumina-ceramic / Polyimide Multilayer Die
lectric Sunstrate, IEEE MTT-S Int.Microwave Symp.D
ig., 1996, pp71-74]. This device uses a polyimide-ceramic multilayer substrate and mounts a plurality of antenna elements having different use frequencies on the same substrate. In this structure, a plurality of active element chips 38 are provided, and the feeder lines 40 mounted in the respective layer structures are provided.
Thus, the plane radiating element 32 is excited through the slot 35. Reference numeral 34 denotes a ground plate, reference numeral 36 denotes a polyimide, reference numeral 37 denotes an alumina ceramic, and reference numeral 41 denotes a via hole. With this structure, a plurality of planar radiating elements are excited by a plurality of active elements, so that the usable fractional bandwidth can be widened.

[0004]

In each of the first and second examples of the above-mentioned conventional apparatus, the active element is integrally formed with the radiating element, and is designed as an antenna apparatus which is attached to the apparatus and moves indoors. Could be possible. However, the first example of the above conventional device is dedicated to transmission. In addition, since the signal powers radiated by a large number of radiating elements are combined in the propagation space, if the number of radiating elements is increased, the transmitted beam becomes narrower, which is not always suitable for a mobile communication antenna device.

[0005] In the second example of the above-mentioned conventional device, the degree of freedom in setting the arrangement position of the planar radiating element is small, and a specific radiation pattern cannot be set. Also, there is no defense against spurious frequencies other than the used frequency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above background, and has as its object to provide an efficient and small-sized antenna device suitable for traveling with the device inside the same room. SUMMARY OF THE INVENTION It is an object of the present invention to provide an antenna device having a structure in which power sharing of an active element is reduced and power combining is performed not on a propagation space but on a radiating element. An object of the present invention is to provide an antenna device having a wide radiation pattern. SUMMARY OF THE INVENTION It is an object of the present invention to provide an antenna device in which a radiating element can have a resonance structure and emit less spurious frequency. An object of the present invention is to provide an antenna device that can be used for both transmission and reception.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an antenna device for integrating an active element and a radiating element into one, in which two points set in one radiating element are out of phase by two active elements. The biggest feature is to excite.

That is, the present invention provides one input / output terminal (1) and a branch circuit (2) connected to the input / output terminal.
And two active elements (3, 4) having the same characteristics and connected to the branch path side of the branch circuit, and two power supply paths (5, 6) respectively connected to the two active elements.
And one planar radiating element (9) connected by the two feeding paths and the two feeding points (7, 8) are integrally mounted. The lengths of the two signal paths through the active elements (3, 4) to the two feed points, respectively, were set so as to excite the two feed points (7, 8) in opposite phases. It is characterized by the following.

It is desirable that the two feeding points (7, 8) are set at symmetrical positions with respect to the center point of the planar radiating element (9).

The numerals in the parentheses are reference numerals in the drawings of the embodiments to be described later, which are provided for easy understanding of the structure of the present invention, and the present invention is limited to the embodiments. Not for understanding.

More specifically, when the effective wavelength in the device corresponding to the frequency to be used is λg, the difference between the lengths of the two signal paths is λg / 2 or an odd multiple thereof. This can be achieved.

[0012] With this structure, a plane radiating element, which is one microstrip antenna radiating element, is excited at two locations with opposite phases, and a more stable standing wave is generated than when a single-point excited radiating element is used. , A good radiation pattern can be obtained. By forming the signal path length difference to be exactly λg / 2 or an odd multiple thereof in order to obtain a signal of the opposite phase, there is no need to provide a complicated phase shift circuit, and the configuration is simplified. You. In addition, since the power generated by the plurality of active elements is combined on one radiating element, a special circuit for combining power is not required, and the configuration is simplified. This has an advantage that the radiation pattern can be easily designed and controlled as desired, as compared with the case where power is combined in space.

Further, in the antenna device of the present invention, the active element can be two oscillating elements which operate synchronously with one pull-in excitation signal (locking signal).

This antenna device can be used for both a transmitting antenna device and a receiving antenna device depending on the connection direction of the active element. However, the active element has an output terminal on the side connected to the planar radiating element, and a branch. It is desirable that the side connected to the circuit be an amplifying element or an oscillating element having a transmission signal input terminal so as to be used as a transmitting antenna device.

In the apparatus of the present invention, the length of the signal path from the input / output terminal to the radiating element is set as described above. In addition, the distance from the active element to the radiating element is set appropriately. Thus, the setting can be made such that the second harmonic or the third harmonic is canceled on the radiating element. That is, the difference between the lengths of the signal paths from the two active elements (3, 4) to the two feeding points (7, 8) is opposite in phase to the second harmonic of the frequency used. Or the two active elements (3,
This can be realized by setting the difference between the lengths of the signal paths from 4) to the two feeding points (7, 8) to be opposite to the third harmonic of the frequency used. it can.

[0016]

(First Embodiment) FIG. 1 is a perspective view showing a three-dimensional structure of an apparatus according to a first embodiment of the present invention. FIG. 1 is a perspective view in which the inside can be seen through from the outer shape so that the entire structure can be easily understood. FIG. 2 is a sectional structural view of the first embodiment. This device has an integrated structure in which two dielectric substrates 10 and 12 sandwich a ground conductor 11 therebetween and are joined to each other. A plane radiating element 9 is formed of a conductive material on the device surface. On the rear surface of the device, one input / output terminal 1, a branch circuit 2 connected to the input / output terminal 1, and two active elements (e.g., Amplifying elements in the embodiment) 3, 4 and two power supply paths 5, connected to the two active elements 3, 4, respectively.
6 are formed.

Two feed points 7 and 8 are set on the surface flat radiating element 9 symmetrically with respect to the center point, and the feed paths 5 and 6 are respectively connected to the two via conductors filled in the via holes 16. Connected to the two feeding points 7 and 8. here,
The lengths of the two signal paths from the branch point of the branch circuit 2 to the two feed points 7, 8 via the active elements 3, 4 respectively excite the two feed points 7, 8 in opposite phases. It is set as follows. Reference numeral 13 denotes a via cover pad, and reference numeral 14 denotes a via hole clearance.

FIG. 3 is an explanatory diagram of a power supply circuit. As shown in FIG. 3, the distance from the feeding point 7 to the active element 3 is A, the distance from the active element 3 to the branch point of the branch circuit 2 is B, the distance from this branch point to the active element 4 is C, Assuming that the distance from the element 4 to the feeding point 8 is D, the effective wavelength in the device corresponding to the used frequency is λg, and (A + B) − (C + D) | = (2n−1) λg / 2 (1 ) Are set as distances A, B, C, and D, respectively. Here, n is an integer of 1 or more.

This configuration is equivalent to exciting the two feeding points 7 and 8 provided on one plane radiating element 9 by just a push-pull circuit, and the outputs of the two active elements 3 and 4 It is synthesized on the radiating element 9. The design of the radiation pattern of the planar radiating element 9 can be changed according to the shape of the planar radiating element 9 and the positions of the two feeding points 7 and 8. In this configuration, two points of one radiating element can be excited with opposite phases without using a special phase inverting element.

The shape of the planar radiating element 9 is a rectangle close to a square in this embodiment, but this shape can be designed variously depending on the use of the device. Further, the shape can be elongated, and the shape need not always be rectangular. By appropriately designing the shape of the planar radiating element 9 and appropriately setting the positions of the two feeding points 7 and 8, it is possible to obtain a radiating element that is in a resonance state at the used frequency. At this time, the imaginary component of the impedance seen from the active circuit side becomes smaller,
The antenna gain can be made close to the gain of the dipole antenna.

Here, after satisfying the above expression (1), the difference (AD) between the distance A and the distance D is the opposite phase between the feeding points 7 and 8 at the second harmonic frequency of the use frequency. When the positions of the active elements 3 and 4 are selected so that
It can be configured to reduce the second harmonic generated in the active elements 3 and 4. When the positions of the active elements 3 and 4 are selected so that the difference (AD) becomes in-phase between the feeding points 7 and 8 at the third harmonic frequency of the use frequency, the third order generated by the active elements 3 and 4 is obtained. It can be configured to reduce harmonics.

(Second Embodiment) FIG. 4 is a structural view of an apparatus according to a second embodiment of the present invention. The device of the second embodiment includes an active element 3
Instead of arranging the active elements 3 and 4 at the same distance from the branch point of the branch circuit 2, the active elements 3 and 4 are arranged at different distances from the branch point. Also in this case, by configuring the circuit so as to satisfy the condition of the above equation (1), the two feeding points 7 and 8 can be similarly excited in opposite phases.

The same reference numerals as in the first embodiment denote the same elements, and a description of the structure will be omitted.

[0024]

As described above, according to the present invention,
With the active element and the radiating element integrated and mounted in one device, an antenna device suitable for a small and efficient mobile device can be provided.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional structural view of the first embodiment of the present invention.

FIG. 3 is a view for explaining a distance of a power supply passage of the device of the first embodiment of the present invention.

FIG. 4 is a structural explanatory view of the second embodiment of the present invention.

FIG. 5 is a structural explanatory view of a conventional device. (A) is an overall plan view, (b) is a main part plan view.

FIG. 6 is an explanatory view of the structure of a conventional device. (A) is a perspective view,
(B) is sectional drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 I / O terminal 2 Branch circuit 3, 4 Active element 5, 6 Feeding path 7, 8 Feeding point 9 Flat radiating element 10 Dielectric substrate 11 Ground conductor 12 Dielectric substrate 13 Via cover pad 14 Via hole clearance 16 Via hole 20 Input terminal 21 Wilkinson divider 22 FET (field effect transistor) 23 single element 24 open stub 32 plane radiating element 34 ground plate 35 slot 36 polyimide 37 alumina ceramic 38 active element chip 40 feed line 41 via hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshikazu Hori 2-3-1, Otemachi, Chiyoda-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 5J021 AA05 AA09 CA06 DB02 DB03 FA05 FA17 FA24 FA26 GA01 GA08 HA05 HA10 JA07

Claims (7)

[Claims] 1. An input / output terminal, a branch circuit connected to the input / output terminal, two active elements having the same characteristics connected to the branch road side of the branch circuit, and the two active elements. Two power supply paths respectively connected to the element, and one planar radiating element connected to the two power supply paths and the two power supply points are integrally mounted on a dielectric substrate; An antenna characterized in that the lengths of two signal paths from a point to each of the two feed points through the active element are set so as to excite the two feed points in opposite phases. apparatus. 2. The antenna device according to claim 1, wherein the difference between the lengths of the two signal paths is λg / 2 or an odd multiple thereof, where λg is the effective wavelength in the device corresponding to the used frequency. 3. The apparatus according to claim 1, wherein a difference between the lengths of the signal paths from the two active elements to the two feeding points is set to be opposite to the second harmonic of the operating frequency. 1
Or the antenna device according to 2. 4. The apparatus according to claim 1, wherein the difference between the lengths of the signal paths from the two active elements to the two feeding points is set to be in phase with the third harmonic of the operating frequency.
Or the antenna device according to 2. 5. The antenna device according to claim 1, wherein the two feeding points are set at positions symmetric with respect to a center point of the planar radiating element. 6. The amplifying element according to claim 1, wherein the active element has an output terminal on the side connected to the planar radiation element and a transmission signal input terminal on the side connected to the branch circuit.
The antenna device as described in the above. 7. The oscillation element according to claim 1, wherein said active element has an output terminal on a side connected to said planar radiating element and an input terminal for a pull-in excitation signal on a side connected to a branch circuit. Antenna device.