JPH02165706A - Dielectric antenna - Google Patents

Abstract

PURPOSE:To improve a gain by providing a dielectric member insertably to a waveguide between an exciter and a dielectric bar, and forming a resonator with the dielectric member and a waveguide part outside the member. CONSTITUTION:The dielectric member 5 is provided insertably to the waveguide 2 between the exciter 4 and the dielectric bar 1, and the dielectric member 5 and the part of the waveguide 2 form the resonator, and degree of coupling between a dielectric line and the exciter 4 can be increased by providing a coupling circuit K1 formed with the resonator and a gap between the exciter 4 and the dielectric member 5, and a coupling circuit K2 formed with the gap between the dielectric member 5 and the dielectric bar 1. ln such a manner, it is possible to sufficiently increase the degree of coupling between the exciter 4 and the dielectric line, and to increase the gain.

Description

DETAILED DESCRIPTION OF THE INVENTION [Main 1, summer and This invention relates to improvements in dielectric antennas.

As a conventional limb blood dielectric antenna, there is one shown in FIG. 4, for example. This is for HE mode, and a rod-shaped exciter 4 is provided by inserting the tip end deep inside the waveguide 2, and a cylindrical exciter 4 is provided inside the waveguide 2 on the tip side of the exciter 4. A support body 3 is provided inside, and a dielectric rod L is passed through the support body 3, and the proximal end side of the dielectric rod 1 is inserted into the waveguide 2, so that electromagnetic waves can be transmitted or received. There is.

Therefore, as equivalently shown in FIG. , and an exciter 4 having impedance ZO constitute a circuit coupled by a coupling circuit K shown by a broken line. In addition, Za
is the impedance of the portion of the dielectric rod l that protrudes outward beyond the insertion portion.

Therefore, in the conventional dielectric antenna having the circuit configuration as described above, the coupling coefficient to the coupling circuit is small, and therefore the gain is small.

The present invention has been made in view of the above circumstances (a dielectric antenna having a structure that can sufficiently increase the degree of coupling between the exciter and the dielectric line and thereby increase the gain). The purpose is to provide

The present invention provides a dielectric antenna that includes an exciter provided deep inside a waveguide and a dielectric rod inserted from the proximal end into the tip of the waveguide. A dielectric member is inserted into the waveguide between the dielectric rod, and a resonator is formed by the dielectric member and the outer waveguide portion.

Sho-U In the present invention, since the dielectric member is inserted into the waveguide between the exciter and the dielectric rod, the dielectric member and the outer waveguide portion form a resonator. and this resonator,
In the coupling circuit formed in the gap between the exciter and the dielectric material,
2 in the coupling circuit formed in the gap between the dielectric member and the dielectric rod, the degree of coupling between the dielectric line and the exciter increases.

The present invention will be specifically explained below. FIG. 1 is a sectional view showing one embodiment of the present invention. In the product of the present invention, a rod-shaped exciter 4 is provided by inserting the tip end into the innermost part of the waveguide 2 having a circular cross section from the outside toward the inside. A cylindrical dielectric member 5 is inserted into the waveguide 2 on the side, and a base end of a circular dielectric rod 1 is inserted into the side waveguide 2 with its tip side protruding outward from the front end of the waveguide 2. It is inserted on the side. The number of dielectric members 5 inserted is one in this example, but two or more may be inserted spaced apart from each other.

The proximal end portion of the dielectric rod 1 that is inserted into the waveguide 2 is inserted into a cylindrical support 3 provided within the waveguide 2. It is supported by the waveguide 2 via a support 3. The support 3 is made of a material with a low dielectric constant that does not disturb the electromagnetic field distribution within the waveguide 2, such as foamed polystyrene.

The dielectric member 5 has a cylindrical support 6 inside the waveguide 2 which has a low permittivity that does not disturb the electromagnetic field distribution within the waveguide 2, as before. It is supported by being inserted into. This dielectric member 5 is made of a dielectric material such as ceramic, and together with the outer waveguide 2 portion, HE + +
form a mode resonator. As the dielectric member 5, it is preferable to use, for example, a dielectric rod whose proximal end is cut to a predetermined length.

The product of the present invention having such a configuration has an equivalent circuit as shown in FIG. That is, the coupling circuit 1 formed in the gap between the exciter 4 and the dielectric member 5, the coupling circuit 2 formed in the gap between the dielectric member 5 and the base end of the dielectric rod 1, and the resonance constitutes a circuit consisting of a bandpass filter circuit, that is, a bandpass filter circuit.

This circuit has a characteristic that, as shown in FIG. 3, there is a frequency band A in which the attenuation (dB (vertical axis)) is extremely small when the frequency (horizontal axis) is a certain magnitude. In addition, in this circuit, the value when the resonator is unloaded is Qo
Then, the load of Kl is Q, l! The magnitudes of the loads Q and 2 can be set to sufficiently small values of about 1720 of Q0, respectively, and therefore the insertion loss IL of the Q, 1 and 002 parts can be set to about 0.2 dB. It becomes possible.

Therefore, by providing the dielectric member 5 so that the frequency band A can be used, the coupling coefficient between the dielectric line and the exciter can be made larger than in the conventional case.

By the way, since the product of the present invention has a filter formed within the waveguide 2, noise components can be removed from the electromagnetic waves captured by the waveguide 2 with the filter as is. As a result, conventionally, the electromagnetic waves captured by the waveguide 2 are converted into electrical signals by the exciter 4, and then signal processing is performed by an external filter or the like via a connecting wire such as a lead wire. This has the advantage that current loss caused by connecting lines and filters can be eliminated.

Note that in the above embodiment, the dielectric rod 1. Although the cross section of the waveguide 2° dielectric member 5 is circular, the present invention is not limited to this, and it goes without saying that the present invention can also be applied to structures where the cross section of each member is rectangular or other shapes. In particular, the dielectric member 5 may be spherical.

Further, in the above embodiment, as shown in FIG. 1, the waveguide 2 has the same cross-sectional size along the direction of propagation of electromagnetic waves, but the present invention is not limited to this. It can also be applied when using a horn type with an open tip. However, in this case, there is a risk that the cross-sectional dimension at the proximal end of the dielectric rod will be larger than the cross-sectional dimension deep inside the waveguide, resulting in lower gain. It is preferable to provide a convex lens on the proximal end surface.

Furthermore, in the above embodiment, H is provided between the exciter 4 and the dielectric rod 1.
Although an E, mode resonator is formed, the present invention is not limited to this and can also be applied to other modes such as TF, O1&,
Of course, the present invention can also be implemented by forming a resonator such as TMo+6 or HEota mode.

As detailed above, according to the present invention, a dielectric member is inserted into the waveguide between the exciter and the dielectric rod, so that the dielectric member and the outer waveguide are connected to each other. The tube portion forms a resonator, the resonator, a coupling circuit formed in the gap between the exciter and the dielectric member, and a coupling circuit formed in the gap between the dielectric member and the dielectric rod. 2 increases the degree of coupling between the dielectric line and the exciter, which has the excellent effect of improving gain.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention, Fig. 2 is an equivalent circuit diagram thereof, Fig. 3 is a graph showing the relationship between frequency and attenuation in the coupling circuit of the invention product, and Fig. 4 is A cross-sectional view showing the configuration of a conventional dielectric antenna, and FIG. 5 is an equivalent circuit diagram thereof. 1... Dielectric rod, 2... Waveguide, 4... Exciter,
5...Dielectric member. Patent applicant: Murata Manufacturing Co., Ltd. Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] (1) In a dielectric antenna comprising an exciter provided deep inside a waveguide and a dielectric rod whose base end is inserted into the tip of the waveguide, between the exciter and the dielectric rod. A dielectric antenna characterized in that a dielectric member is inserted into a waveguide, and a resonator is formed by the dielectric member and an outer waveguide portion.