JPH039602A - Microwave receiver - Google Patents

Abstract

PURPOSE:To obtain a miniaturized microwave receiver by using a print patch antenna. CONSTITUTION:Microwaves received with patch antennas 21-24 are taken out with signal take-out lines 21b-24b, and are synthesized at midpoints P1 and P2, and are transmitted on a transmission line 3 via connection lines 31 and 32. At a local oscillation part L, a local signal is oscillated at a FET 42 from the upper part of a metallic case 7 with a space adjusted with a screw 7a for adjustment and a dielectric 41 for local oscillation. A received microwave signal transmitted on the transmission line 3 and the local signal oscillated at the local oscillation part L are synthesized at the 1/4lambda part of a pattern 4a, and is mixed at a mixing part M with a mixer diode, and is amplified at an intermediate frequency amplifying part N with an IC element 6. By forming a required circuit on the same substrate where a patch antenna is provided, a signal processing can be performed compactly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a small and thin microwave receiver capable of receiving microwave signals.

(Prior art) Conventionally, it is also called SHF wave, and its frequency range is 3GH,
Microwaves ranging from ~30 GHz are used for microwave relays, etc. However, as the frequency increases to this extent, the properties of radio waves become similar to light and sound waves, so medium waves (300 GHz) are used for transmitting and receiving radio waves. Transmission paths and antennas different from those for short waves (3 MHz to 30 MHz) and short waves (3 MHz to 30 MHz) are used.

Therefore, when considering conventional microwave receivers, the antenna is generally a parabolic antenna or a 7ft antenna. An i-horn is used to transmit radio waves received by an antenna to a signal processing circuit using a waveguide or microstrip line, where signal processing such as amplification and mixing is performed, but parabolic antennas and electromagnetic horns are large and made of metal. Because of the large size and weight of the receiver, it was difficult to miniaturize the entire receiver to make it convenient to carry. Furthermore, the above-described structure requires a large number of circuit components, which also causes high costs.

Incidentally, relatively simple microwave receivers have recently been used in automatic building doors, automobile radar receivers, and automobile speed measuring devices. In this type of microwave receiver, a mixing diode and a local oscillator (for example, a Gunn diode) are built into a die-cast horn antenna, and after mixing in the space inside the waveguide and the mixer diode, Intermediate frequency amplification is carried out on a separate circuit board, but the size of the horn antenna itself is limited, making it difficult to miniaturize, and the local oscillator, which uses a Gunn diode, consumes a lot of power and generates heat. The problem was that it was big.

(Objects and Structure of the Invention) The present invention has been made in view of the above points, and focuses on a printed patch antenna formed on a substrate by etching technology, etc., and uses this printed patch antenna to create a microwave receiver. To achieve this goal, a signal processing circuit for processing the microwaves received by the printed patch antenna was formed on the same substrate as the printed punch antenna.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 is a perspective view showing an embodiment of a microwave receiver module according to the present invention, taken out from an external case.

The module has four rectangular microstrip bunch antennas (hereinafter referred to as "batch antennas") 21, 22, 23, 24 on one side of a dielectric substrate (for example, Teflon glass fiber type) with copper coating on both sides, and a transmission The line 3 and local oscillation patterns 4a, 4b, and 4c are formed by etching technology, and a local oscillation dielectric 41 and a local oscillation FET 42 are arranged near the local oscillation patterns 48 to 4c. A mixer diode 5 is arranged near the tip of the transmission line 3, and an IC element 6 for intermediate frequency amplification is arranged near the mixer diode 5.
is located.

Here, the circuit configuration of the module will be described in more detail. The batch antennas 21 to 24 have a square shape, and a notch is formed in one piece of each batch antenna. - As an example, the batch antenna 21 is shown in FIG. 2, but if the length of one side of the square batch antenna is a, then
The width and depth of the notch 21a are ka (k is a constant,
For example, a signal extraction line 21b is patterned from the center of the notch 21a of the batch antenna 21.
The line width of is determined as αk (α is a constant, for example 2) in relation to the constant k. Batch antenna 21
Signal extraction from 492 l b and batch antenna 23
The signal extraction lines 23b from the batch antenna 22 and the signal extraction lines 24b from the batch antenna 24 are similarly connected to each other. Approximately midpoints PI and 22 of these connection lines are connected by a patterned connection line 31 with a line width calculated in advance, and a connection line 32 with a line width calculated in advance is connected from approximately the midpoint Pff of this connection line 31. It is connected to the transmission line 3 by.

On the other hand, as the local oscillator L (the part surrounded by the broken line),
There are three patterns 4 for local oscillation near the edge of the board l.
3 to 4c are formed, and each pattern is connected to each of the three terminals of the FET 42 for local oscillation, that is, the gate, source, and train. Among the local oscillation patterns 43 to 4c, the pattern 4a is formed close to the transmission line 3 with a length 1/4 corresponding to 1/4 of the wavelength of the received microwave. Furthermore, a disk-shaped local oscillation dielectric 4I is arranged between the local oscillation patterns 4a and 40.

Next, on the substrate 1, a mixer part M (shown surrounded by a broken line) consisting of a mixer diode 5 and a resistance element is provided at the tip of the transmission line 3. An IC element 6 and a resistance element for intermediate frequency amplification are arranged near this mixer part M and in a position parallel to the local oscillation part, and form an intermediate frequency amplification part N (the part surrounded by a broken line). are doing.

The local oscillation section on the substrate 1, the mixer part M, and the intermediate frequency amplification section N are shielded from above the substrate 1 by a metal case 7 for electric field shielding. The metal case 7 is provided with a space capacitance adjusting screw 7a for adjusting the frequency of the local oscillation dielectric 41 on the substrate 1, and can be adjusted vertically from above with a screwdriver or the like.

Next, the circuit operation of the above module will be briefly explained.

The microwave signals received by the patch antennas 21 to 24 are transmitted from the cutout portion of each patch antenna to signal extraction lines 21b to 24.
24b and taken out, midpoint P□.

It is synthesized at P2 and connected to the transmission line 3 via connection lines 31 and 32.
transmitted to.

On the other hand, in the local oscillation section, a local signal is oscillated by the FET 42 due to the space adjusted from above the metal case 7 by the adjustment space a and the high dielectric constant of the local oscillation dielectric 41.

The received microwave signal transmitted through the transmission line 3 and the local signal oscillated by the local oscillator are shown in pattern 4a.
The signals are combined at the /4 input section, mixed by mixer diode 5 at mixer section M, and the mixed signal is amplified by a submultiple dB intermediate frequency by IC element 6 at adjacent intermediate frequency amplification section N.

The circuit functions of the module are as described above, and the microwave signal whose intermediate frequency has been amplified by this module is transmitted to another board (not shown) provided on the back side of the board via a transmission line (not shown) passing through the through hole of board l. The signal is then transmitted to the station, where it undergoes the signal processing necessary for alarms, displays, etc.

In this way, high frequency amplification, local oscillation using a dielectric, mixing,
By forming the circuits necessary for intermediate frequency amplification, etc., it becomes possible to compactly process microwave signals with less transmission loss.

Although the above module has a local oscillation section, a mixing section, and an intermediate frequency amplification section, these are only examples, and the circuit configuration can be changed depending on the application of the circuit.
What is important in the present invention is that a circuit for processing microwave signals received by the printed patch antenna is formed on the same substrate as the printed patch antenna, and the circuit configuration is is not a problem.

Further, the present invention can be realized not only with a microstrip patch antenna but also with a microstrip line antenna or a microstrip slot antenna by appropriately selecting circuit constants and line constants.

(Effects of the Invention) As explained above, in the present invention, the printed pouch antenna and the circuit for processing the microwave signal received by the printed patch antenna are formed on the same substrate, so that the microwave receiver can It can be made smaller, thinner, and more compact.

Therefore, it has many advantages over conventional microwave receivers of this type, such as being convenient to carry, reducing costs by reducing the number of parts, and reducing transmission loss by shortening the signal transmission path on the circuit.

Furthermore, by extracting the signal from the notch formed in the printed patch antenna, the line width of the signal extraction line can be made thicker, making it possible to design a circuit that overcomes the accuracy limitations of etching technology.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of a microwave receiver module according to the present invention, and FIG. 2 is a diagram showing the shape of a patch antenna used in the module of the present invention. 1-... Board, 21-24... Patch antenna, 31
．． 32...Connection line, 3...Transmission line, 43~4c・
... Pattern, 41 ... Dielectric for local oscillation, 42
... FET for local oscillation, 5 ... Mixer diode, 6 ... - IC element for intermediate amplification

Claims (2)

[Claims] (1) A microwave receiver characterized in that a signal processing circuit for processing microwave signals received by the printed patch antenna is formed on a substrate on which the printed patch antenna is formed. (2) The printed patch antenna according to claim 1, wherein the printed patch antenna is a rectangular microstrip patch antenna, and the microstrip patch antenna has a notch on one side, and a signal extraction line extends from the notch. Microwave receiver.