WO2002067365A1

WO2002067365A1 - Nrd guide mixer

Info

Publication number: WO2002067365A1
Application number: PCT/KR2002/000133
Authority: WO
Inventors: Cheon Woo Shin
Original assignee: Nrdtech Co., Ltd
Priority date: 2001-02-20
Filing date: 2002-01-29
Publication date: 2002-08-29
Also published as: KR20010044422A; KR100358971B1; CN1491453A

Abstract

The present invention relates to NRD guide mixer. According to the present invention, the balance mixer comprises: a Schottky diode mount inserted into the center of transmission line, which has two detection Schottky diodes and has a different route for the IF output from the bias route, and the antenna of which is symmetrical horizontally and vertically; an LSM mode suppresser inserted into the input part of the LO for the LOs propagation in accordance with LSE01 mode; and an LSE mode suppresser inserted into the input part of the RF for the RFs propagation in accordance with LSM01 mode. The single mixer comprises: a Schottky diode mount inserted into the center of transmission line, which has one detection Schottky diode and has a different route for the IF output from the bias route, and the antenna of which is asymmetrical; an LSM mode suppresser; and an LSE mode Suppresser.

Description

NRD GUIDE MIXER

TECHNICAL FIELD

The present invention relates to a mixer which makes LO (Local Oscillation) wave enter an NRD Guide using LSE01 mode. The size of the mixer may be made smaller according to the present invention.

BACKGROUND ART

Recently, as millimeter wave attracts more and more interests, various millimeter wave integrated circuit elements using an NRD Guide (Non Radiative

Dielectric waveGuide) are being introduced in the related art.

Passive elements such as a band, a directional coupler, a filter, a circulator, etc. and active elements such as a Gunn oscillator, a mixer, a modulator, an amplifier, etc. are the examples of such millimeter wave integrated circuit elements. These elements are assembled into devices such as a transceiver, a radar, etc., improving the performance of the devices.

The related art mixer that uses an NRD Guide is a balanced mixer comprising two beam lead type-Schottky barrier diodes and a directional coupler. Because a directional coupler is essential for this structure, it is difficult to downsize the mixer.

DISCLOSURE OF THE INVENTION

According to the first preferred embodiment of the present invention, LO waves enter an NRD Guide (3) in LSE01 mode and reach a diode mount (6), which has the symmetrical structure and on which two Schottky diodes are mounted, passing through a vertical LSM mode suppressor (4). RF (Received Frequency) waves enter an NRD Guide (7). in the opposite side in LSMOl mode. Furthermore, the balanced mixer according to the first preferred embodiment of the present invention is built by inserting an LSE mode suppressor (8) in order to suppress LSE mode and by inserting a high permittivity sheet for impedance matching with the diode mount (6). A horizontal LSM mode suppressor may be used for the first embodiment of the present invention instead of a vertical LSM mode suppressor.

According to the second preferred embodiment of the present invention, LO waves enter an NRD Guide (3) in LSE01 mode and reach a diode mount (11), which has the asymmetrical structure and on which one Schottky diode is mounted, passing through a vertical LSM mode suppressor (4). RF (Received Frequency) waves enter an NRD Guide (7) in the opposite side in LSMOl mode. Furthermore, the single mixer according to the second preferred embodiment of the present invention is built by inserting an LSE mode suppressor (8) in order to suppress LSE mode and by inserting a high permittivity sheet for impedance matching with the diode mount (11). A horizontal LSM mode suppressor may be used for the second embodiment of the present invention instead of a vertical LSM mode suppressor.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a balanced mixer with the illustrations of the flow of LO waves and RF waves.

Figure 2 illustrates the structure of a Schottky diode mount of a balanced mixer and the circuit for bias and IF(Intermediate Frequency) outputs.

Figure 3 illustrates a top view of an antenna part of a balanced mixer. Figure 4 illustrates a perspective view of a horizontal LSM mode suppressor. Figure 5 is a graph that illustrates the pass characteristic of a horizontal LSM mode suppressor.

Figure 6 illustrates a perspective view of a vertical LSM mode suppressor. Figure 7 is a graph that illustrates the pass characteristic of a vertical LSM mode suppressor.

Figure 8 illustrates an exploded perspective view of an LSE mode suppressor. Figure 9 illustrates a perspective view of a single mixer with the flow of LO waves and RF waves.

Figure 10 illustrates the structure of a Schottky diode mount of a single mixer and the circuit for bias and IF outputs.

Figure 11 illustrates a top view of the antenna part of a single mixer. Figure 12 is a graph that illustrates the conversion loss when a single mixer is used, wherein the thickness of the high permittivity sheet is 0.15mm and the length of an NRD Guide between the high permittivity sheet and the LSE mode suppressor is 2.15mm.

**Description of the codes at important parts of diagrams**

1 : Upper Conducting Plate

2 : Lower Conducting Plate 3, 5, 7, 13 : NRD Guide 4 : LSM Mode Suppressor

6 : Diode Mount of a Balanced Mixer 8 : LSE Mode Suppressor 9, 10, 12 : Schottky Diode

11 : Diode Mount of a Single Mixer 14 : Metal Thin Film (in the shape of Choke) a : Height of NRD Guide b : Width of NRD Guide c : Length of Metal Strip of a Vertical LSM Mode Suppressor or Width of Metal Plate of a Horizontal LSM Mode Suppressor, which is inserted into an NRD Guide s : Width of Metal Strip of a Vertical LSM Mode Suppressor which is inserted into an NRD Guide wl : Width of Metal Strip which has smaller size at Choke Structure of an LSE Mode Suppressor w2 : Width of Metal Strip which has bigger size at Choke Structure of an LSE Mode Suppressor

BEST MODE FOR CARRYING OUT THE INVENTION (First preferred embodiment)

LO (LSE01) wave enters the NRD Guide (3) and simultaneously RF (LSMOl) wave enters the NRD Guide (7) of the opposite side in the balanced mixer of Figure 1. In order to suppress LSM mode that exists in the waveguide, a vertical LSM mode suppressor (4) is inserted into the side of the NRD Guide that LO wave enters. In order to suppress LSE mode that exists in the waveguide, an LSE mode suppressor (8) is inserted into the side of the NRD Guide that RF wave enters. LO and RF, transferred through the respective routes, are modes that cross each other perpendicularly.

Figure 2 illustrates the structure of a diode mount (6) of the balanced mixer which has a metal thin film antenna that may simultaneously receive LO and RF modes that cross each other perpendicularly. Measurements set forth in the preferred embodiment of the present invention are for 60GHz. Two HSCH9101 Schottky barrier diodes produced by HP are mounted in the preferred embodiment of the present invention. Figure 3 illustrates the antenna part of the diode mount (6). LSM mode of RF wave is received by the antenna aligned horizontally and LSE mode of LO wave is received by the antenna aligned vertically. Then, they are mixed together.

Figure 4 includes the structure of a vertical LSM mode suppressor that suppresses LSM mode which might be included in LO of Figure 1. In the present invention, the width of metal strip is 0.2mm, the height (a) of the NRD Guide is 2.5mm and the width (b) of the NRD Guide is 2.25mm.

Figure 5 illustrates the pass characteristic of the vertical LSM mode suppressor shown in Figure 4 corresponding to the ratio of the length of metal strip (c) to the width of NRD Guide (b). It is found that the transmission loss is about -40dB when the ratio (c/b) is 0.85.

Figure 6 illustrates the structure of a horizontal LSM mode suppressor. The horizontal LSM mode suppressor is built by inserting a metal plate into the center of the NRD Guide parallel to the direction of the NRD Guide's width. The pass characteristic is different corresponding to the width (c) and the length (1) of the metal plate. The pass characteristic is illustrated in Figure 7. It is found that the pass characteristic does not change much corresponding to the length (1) of the metal plate but the pass characteristic changes greatly corresponding to the width (c) of the metal plate.

Figure 8 illustrates an exploded perspective view of an LSE mode suppressor that may suppress LSE mode by inserting a metal thin film in the shape of choke into the NRD Guide that RF enters. The wider width of the metal strip (w2) of the choke structure is 2.0mm and the narrower width (wl) of the metal strip choke is 0.2mm. Metal strips are aligned with the gap of 0.9mm, that is, λ/4. (Second preferred embodiment)

In the single mixer shown in Figure 9, LO (LSE01) enters the NRD Guide (3) and RF (LSMOl) enters the NRD Guide (7) in the opposite side simultaneously. In order to suppress LSM mode that might exist in the waveguide, a vertical LSM mode suppressor (4) is inserted into the side of the NRD Guide that LO wave enters. In order to suppress LSE mode that might exist in the waveguide, an LSE mode suppressor (8) is inserted into the side of the NRD Guide that RF enters. LO and RF, transferred through the respective routes, are modes that cross each other perpendicularly.

Figure 10 illustrates the structure of a diode mount (11) of a single mixer which has a metal thin film antenna that receives vertically crossing modes of LO and RF simultaneously. Measurements set forth in this preferred embodiment of the present invention are for 60GHz. Only one HSCH9101 Schottky barrier diode produced by HP is mounted. The diode mount has an asymmetrical structure.

Figure 11 illustrates the antenna part of the diode mount. As with the balanced mixer, LSM mode of RF is received by the antenna aligned horizontally and LSE mode of LO is received by the antenna aligned vertically. Then, they are mixed together. The structure is asymmetrical. Only one Schottky diode is used.

Figure 12 illustrates the conversion loss corresponding to the IF frequency range, when IF is outputted by using a single mixer. It is found that the conversion loss has the constant value of lOdB up to the level of 500MHz. At this time, the bias current is 5.67mA, the LO frequency is 59.5GHz and the RF frequency is 59.2GHz.

INDUSTRIAL APPLICABILITY

According to the present invention, a mixer may be made small and simple by using both of the two modes existing in the NRD Guide and not using a directional coupler. Also, according to the present invention, the cost may be effectively reduced by building a single mixer with one diode. If the mixer that uses both of the two modes (LSE mode and LSM mode) is completed, the NRD Guide may be applied more broadly and effectively than it used to be.

Claims

WHAT IS CLAIMED IS:

1. A balanced mixer, wherein:

LO wave enters an NRD Guide (3) in LSE01 mode; the LO wave reaches a diode mount (6) of symmetrical structure, on which two Schottky diodes are mounted, passing through a vertical LSM mode suppressor (4); RF wave enters an NRD Guide (7) in the opposite side in LSMOl mode; an LSE mode suppressor (8) is inserted in order to suppress LSE mode; and a piece of high permittivity sheet is inserted for impedance matching with the diode mount (6).

2. The balanced mixer of claim 1, wherein a horizontal LSM mode suppressor is inserted instead of the vertical LSM mode suppressor.

3. A single mixer, wherein: LO wave enters an NRD Guide (3) in LSE01 mode; the LO wave reaches a diode mount (11) of asymmetrical structure, on which one Schottky diode is mounted, passing through a vertical LSM mode suppressor (4); RF wave enters an NRD Guide (7) in the opposite side in LSMOl mode; an LSE mode suppressor (8) is inserted in order to suppress LSE mode; and a piece of high permittivity sheet is inserted for impedance matching with diode mount (11).

4. The single mixer of claim 3, wherein a horizontal LSM mode suppressor is inserted instead of the vertical LSM mode suppressor.

5. The balanced mixer of claim 1, wherein air gaps are placed at the boundaries from NRD Guides to the diode mount to have the narrow band and thus the VSWR (Voltage Standing Wave Ratio) characteristic is improved.

6. The single mixer of claim 3, wherein air gaps are placed at the boundaries from NRD Guides to the diode mount to have the narrow band and thus the VSWR (Voltage Standing Wave Ratio) characteristic is improved.