CN1528031A - Non-radiative dielectric waveguide horn antenna - Google Patents

Abstract

The present invention relates to a horn antenna for an NRD guide. In case that a horn antenna of the prior art is installed in an NRD guide where the distance between the upper and lower conductor plates is not greater than lambda , a discontinuous region, where an electric wave cannot pass through, exists from the NRD guide to the horn antenna aperture which is lambda /2 distant from the NRD guide. As the result, a loss occurs lowering the gain of the horn antenna. The present invention provides a horn antenna which has the appropriate opening angle through an assigned angle intended to minimize the above-mentioned region of lambda /2 and below. Consequently, the present invention implements a horn antenna for an NRD guide with excellent radiation pattern, where the discontinuous region of an electric wave is minimized and thus the efficiency of the antenna is heightened.

Description

Nonradiative dielectric (NRD) waveguide trumpet antenna

Technical field

Nonradiative dielectric (NRD) waveguide has been considered to a kind of effective millimetre integrated circuit because of its low-loss rate and radiationless characteristic.

Background technology

The NRD waveguide is a kind of structure, and wherein: parallel conductive plates is arranged with the distance of the half wavelength that is equal to or less than frequency of utilization each other; Insert medium strip between two parallel conductive plates, the height of this medium strip equals the gap of two parallel conductive plates, and width is a definite steady state value.

A kind of flagpole antenna has been used as the antenna of the millimetre integrated circuit that uses the NRD waveguide, because generally speaking, flagpole antenna has advantage in impedance and waveguide aspect being complementary.The gain of flagpole antenna approximately is 17dB.

Yet along with the minimizing of NRD duct width, flagpole antenna can be exposed to outside upper strata/lower floor's conductive plate, and like this, its superior function will worsen along with external environment condition, and may be easy to fracture because of outside natural force.In addition, it also is difficult to prevent the leakage of ripple.

Summary of the invention

The invention provides a kind of NRD waveguide trumpet antenna 6, it has very strong adaptability and has mechanical strength external environment condition, has kept the performance of the employed flagpole antenna of NRD waveguide aspect gain and directivity of the millimere-wave band of correlation technique simultaneously.

A kind of NRD waveguide cone 4 is used as the waveguide of NRD waveguide trumpet antenna 6.

NRD waveguide trumpet antenna 6 has the aperture of a height greater than width.

Description of drawings

Fig. 1 is the NRD waveguide trumpet antenna perspective view of most preferred embodiment of the present invention;

Fig. 2 is the front view of NRD waveguide trumpet antenna;

Fig. 3 is the sectional view of NRD waveguide trumpet antenna;

Fig. 4 is the top view of NRD waveguide trumpet antenna;

Fig. 5 is the top view of NRD waveguide trumpet antenna, and this antenna is used to measure VSWR (voltage standing wave ratio) and the gain by the decision of cone 4 length;

Fig. 6 has shown by the VSWR of cone 4 length decision and the measurement result of gain;

When the length that Fig. 7 has described cone 4 is optimum value 5.5mm, gain on the xz plane and directivity;

When the length that Fig. 8 has described cone 4 is optimum value 5.5mm, gain on the xy plane and directivity;

Fig. 9 has described directivity and the aperture area efficient that depends on frequency;

Figure 10 has illustrated phase efficiency and the aperture area efficient that depends on the phase error on E and the H plane.

The code description of vitals in the accompanying drawing:

The 1st, the upper strata conductive plate; The 2nd, lower floor's conductive plate; The 3rd, dielectric waveguide (NRD waveguide); The 4th, as the cone of NRD waveguide trumpet antenna wave guide; The 5th, be used for fixing the conductive plate of NRD waveguide trumpet antenna on upper strata/lower floor's conductive plate; The 6th, NRD waveguide trumpet antenna.

Preferred forms of the present invention

Below, in conjunction with the accompanying drawings to most preferred embodiment of the present invention to being further described.

The present invention relates to a kind of horn antenna as shown in Figure 1.The formation of NRD waveguide is: dielectric waveguide 3 is installed between upper strata conductive plate 1 and the lower floor's conductive plate 2; NRD waveguide trumpet antenna 6 by one fixedly conductive plate be fixed on upper strata conductive plate 1 and the lower floor's conductive plate 2; The millimeter wave that is transferred in the NRD waveguide is directed on the NRD waveguide trumpet antenna 6 by cone 4.

Gap design between upper strata conductive plate 1 and the lower floor's conductive plate 2 is 2.25mm, but this size is less than the half wavelength of frequency of utilization in the 60GHz scope.The width of dielectric waveguide 3 is 2.5mm, but is the half wavelength of frequency of utilization.

Fig. 2 is the direction diagram NRD waveguide trumpet antenna of propagating from ripple, and narrow part is the part that waveguide is inserted, and its height (a) is 2.25mm, and this height is identical with the gap of upper strata conductive plate and lower floor's conductive plate; In order not influence wave propagation, the gap of λ/4 must be arranged, between (b) from the transmission line to the width so width (b) is got 6.25mm.And, in order to make the discontinuity zone minimum of ripple, to the angle of direction of wave travel be 48.35 ° to make the height (A) of NRD waveguide trumpet antenna aperature be 27mm that to the angle of direction of wave travel being 14.5 ° by the setting horizontal direction, to make the width (B) of NRD waveguide trumpet antenna aperature be 13mm by setting vertical direction.The aperture is 27.25mm to the spacing of the contact point of NRD waveguide 3 and cone 4.

Phase error in the horn antenna is a factor that influences the horn antenna effect.In common aperture antenna, frequency is high more, and it is big more to gain.Yet, saturation condition as shown in Figure 9 can appear in high frequency.When phase error increased, this can cause aperture area efficient to reduce.Aperture area efficient can be used following formulate:

${\mathrm{\ϵ}}_{\mathrm{ap}}={\mathrm{\ϵ}}_t{\mathrm{\ϵ}}_{\mathrm{ph}}={\mathrm{\ϵ}}_t{\mathrm{\ϵ}}_{\mathrm{ph}}^E{\mathrm{\ϵ}}_{\mathrm{ph}}^H$

$D=\frac{4\mathrm{\π}}{{\mathrm{\λ}}^2}{\mathrm{\ϵ}}_{\mathrm{ap}}\mathrm{AB}$

Phase error should be greater than π/8=22.5 °.Horn antenna of the present invention satisfies this scope of phase error.In order to obtain required effect as shown in figure 10, (A, B) size is determined by following formula in the aperture.Among the present invention, select suitable aperture area efficient on E plane and the H plane according to falling phase error.

$t=\frac{1}{8}{\left(\frac{A}{\mathrm{\λ}}\right)}^2\frac{1}{R_0^H/\mathrm{\λ}}$

$S=\frac{1}{8}{\left(\frac{B}{\mathrm{\λ}}\right)}^2\frac{1}{R_0^E/\mathrm{\λ}}$

RO is the distance that the center branch on E or H plane is clipped to aperture center.In fact, for in the requirement of satisfying NRD waveguide trumpet antenna aspect these characteristics of phase error, effect, directivity and gain, angle from the H plane to the aperture must be 14 °～35 °, and the E plane must be between 45 °～56 ° to the angle in aperture.

A special teflon thin slice, its thickness is 0.1mm, is attached on the loudspeaker aperture to prevent that ripple from leaking.

Fig. 3 and Fig. 4 are the sectional view and the top view of NRD waveguide trumpet antenna.

Shown in Figure 5, cone 4 is inserted in the NRD waveguide trumpet antenna 6.The length of cone 4 is depended in the variation of gain and VSWR characteristic.Fig. 6 illustrates VSWR and the length of cone 4 is depended in gain, gains height and VSWR is low when figure can find that length when cone 4 is between 5mm～6mm.

Correspondingly, in most preferred embodiment of the present invention, the length of getting cone 4 is that 5.5mm is to obtain optimal results.Resulting gain characteristic as shown in Figure 7 and Figure 8.Fig. 7 has described on the z axle that is based upon the xz plane gain mode from 0 °～180 °; Fig. 8 has described on the x axle that is based upon the xy plane gain mode from-90 °～90 °.

According to most preferred embodiment of the present invention, the gain of NRD waveguide trumpet antenna approximately is 16.5dB.

Industrial applicibility

The invention provides a kind of NRD waveguide trumpet antenna 6, it has very strong adaptability to external environment condition And in millimere-wave band, has a mechanical strength.

The waveguide of NRD waveguide trumpet antenna is made up of a cone 4 that is connected in the NRD waveguide 3, therefore The gain of NRD waveguide trumpet antenna of depending on the length of cone 4 can keep almost and flagpole antenna one The gain of sample.

Claims (2)

1, a kind of NRD waveguide trumpet antenna that applies to millimere-wave band, therein, the angular aperture on the horn antenna vertical plane is 48.35 ° at least, the angular aperture on the horizontal plane is 14.5 °, and is combined in order to improve gain at its structure inner waveguide and loudspeaker.

2, NRD waveguide trumpet antenna as claimed in claim 1, therein, the special teflon thin slice that thickness is 0.1mm is attached on the loudspeaker aperture to prevent that ripple from leaking.

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