CN1528031A - Non-Radiating Dielectric (NRD) 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

Non-Radiating Dielectric (NRD) Waveguide Horn Antenna

technical field

Non-radiative dielectric (NRD) waveguides have been considered as an effective millimeter-wave integrated circuit due to their low loss rate and non-radiative properties.

Background technique

An NRD waveguide is a structure in which: parallel conductive plates are arranged at a distance equal to or less than half a wavelength of the frequency of use; a dielectric strip is inserted between the two parallel conductive plates, and the height of the dielectric strip is equal to that of the two parallel conductive plates The width of the gap is a definite constant value.

A rod antenna has been used as an antenna for mmWave integrated circuits using NRD waveguides because, in general, rod antennas have advantages in impedance matching with waveguides. The gain of the rod antenna is about 17dB.

However, as the width of the NRD waveguide decreases, the rod antenna will be exposed from the upper/lower conductive plates, so that its superior performance will deteriorate with the external environment, and it may be easily broken by external natural force. In addition, it is also difficult to prevent the leakage of waves.

Contents of the invention

The present invention provides a NRD waveguide horn antenna 6, which has strong adaptability to the external environment and has mechanical strength, while maintaining the gain and directivity of the rod antenna used in the millimeter wave band NRD waveguide of the related art performance.

An NRD waveguide cone 4 is used as the waveguide of the NRD waveguide horn antenna 6 .

The NRD waveguide horn antenna 6 has an aperture whose height is greater than its width.

Description of drawings

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

Figure 2 is a front view of the NRD waveguide horn antenna;

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

Figure 4 is a top view of the NRD waveguide horn antenna;

Fig. 5 is the top view of NRD waveguide horn antenna, and this antenna is used for measuring VSWR (voltage standing wave ratio) and gain determined by the length of cone 4;

Fig. 6 shows the measurement results of VSWR and gain determined by the length of the cone 4;

Figure 7 describes the gain and directivity on the xz plane when the length of the cone 4 is the optimal value of 5.5 mm;

Figure 8 describes the gain and directivity on the xy plane when the length of the cone 4 is the optimal value of 5.5 mm;

Figure 9 depicts the frequency-dependent directivity and aperture area efficiency;

Figure 10 illustrates the phase efficiency and aperture area efficiency depending on the phase error on the E and H planes.

Code description of important components in the attached drawings:

1 is the upper conductive plate; 2 is the lower conductive plate; 3 is the dielectric waveguide (NRD waveguide); 4 is the cone used as the NRD waveguide horn antenna waveguide; 5 is used to fix the NRD waveguide horn antenna on the upper/lower conductive plate The conductive plate; 6 is the NRD waveguide horn antenna.

BEST MODE FOR CARRYING OUT THE INVENTION

Below, the preferred embodiment of the present invention will be further described in conjunction with the accompanying drawings.

The present invention relates to a horn antenna as shown in FIG. 1 . The composition of the NRD waveguide is: the dielectric waveguide 3 is installed between the upper conductive plate 1 and the lower conductive plate 2; the NRD waveguide horn antenna 6 is fixed on the upper conductive plate 1 and the lower conductive plate 2 through a fixed conductive plate; transmitted to the NRD waveguide The millimeter wave on the surface is guided to the NRD waveguide horn antenna 6 through the cone 4 .

The gap between the upper conductive plate 1 and the lower conductive plate 2 is designed to be 2.25 mm, which is smaller than half the wavelength of the usable frequency in the range of 60 GHz. The width of the dielectric waveguide 3 is 2.5 mm, which is half the wavelength of the usable frequency.

Figure 2 is an illustration of the NRD waveguide horn antenna from the direction of wave propagation. The narrow part is the part where the waveguide is inserted, and its height (a) is 2.25mm, which is the same as the gap between the upper conductive plate and the lower conductive plate; in order not to affect For wave propagation, there must be a gap of λ/4 from the transmission line to the width (b), so the width (b) is 6.25mm. Moreover, in order to minimize the discontinuity of the wave, the height (A) of the NRD waveguide horn antenna aperture is 27 mm by setting the angle from the vertical direction to the wave propagation direction as 48.35°, and by setting the horizontal direction to the wave propagation direction The angle of 14.5° makes the width (B) of the NRD waveguide horn antenna aperture 13mm. The spacing from the aperture to the contact point of the NRD waveguide 3 with the cone 4 is 27.25 mm.

Phase error in the horn antenna is a factor that affects the efficacy of the horn antenna. In a common aperture antenna, the higher the frequency, the greater the gain. However, a saturated state as shown in Fig. 9 occurs at high frequencies. This results in reduced aperture area efficiency as the phase error increases. The aperture area efficiency can be expressed by the following formula:

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; ap</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; pH</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; pH</span>}}^{\mathrm{<span\; class="notranslate">\; E.</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; pH</span>}}^{\mathrm{<span\; class="notranslate">\; h</span>}}$

$\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; ap</span>}}\mathrm{<span\; class="notranslate">\; AB</span>}$

The phase error should not be greater than π/8=22.5°. The horn antenna of the present invention satisfies this range of phase error. In order to obtain the desired efficacy as shown in Figure 10, the size of the aperture (A, B) is determined by the following formula. In the present invention, the appropriate aperture area efficiency on the E plane and the H plane is selected according to the phase error range.

$\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 8</span>}}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; A</span>}}{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}$

$\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 8</span>}}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; B</span>}}{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="R"\; filenames="A0280495800121.png"\; state="\{\{state\}\}">R</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; E.</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}$

RO is the distance from the center of the E or H plane respectively to the center of the aperture. In fact, in order to meet the requirements of the NRD waveguide horn antenna in terms of phase error, power efficiency, directivity and gain, the angle from the H plane to the aperture must be between 14° and 35°, and the angle from the E plane to the aperture must be Between 45° and 56°.

A Teflon sheet, 0.1 mm thick, is attached to the horn aperture to prevent wave leakage.

Figures 3 and 4 are cross-sectional and top views of the NRD waveguide horn antenna.

As shown in FIG. 5 , the cone 4 is inserted into the NRD waveguide horn antenna 6 . Gain and VSWR characteristics vary depending on the length of the cone 4 . Figure 6 illustrates that VSWR and gain depend on the length of the cone 4, and it can be found from the figure that the gain is high and the VSWR is low when the length of the cone 4 is between 5 mm and 6 mm.

Correspondingly, in the preferred embodiment of the present invention, the length of the cone 4 is chosen to be 5.5 mm to obtain the best results. The resulting gain characteristics are shown in Figures 7 and 8. Figure 7 describes the gain pattern from 0° to 180° on the z-axis of the xz plane; Figure 8 describes the gain pattern from -90° to 90° on the x-axis of the xy plane.

According to the preferred embodiment of the present invention, the gain of the NRD waveguide horn antenna is about 16.5 dB.

Industrial Applicability

The present invention provides an NRD waveguide horn antenna 6, which has strong adaptability to the external environment and has mechanical strength in the millimeter wave band.

The waveguide of the NRD waveguide horn antenna consists of a cone 4 connected to the NRD waveguide 3, so the gain of the NRD waveguide horn antenna depending on the length of the cone 4 can maintain almost the same gain as the rod antenna.

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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