JPH02266704A - Microstrip array antenna - Google Patents

Abstract

PURPOSE:To attain the easy initial capture of a satellite and the acceleration of tracing of the satellite by providing a microstrip antenna and plural microstrip antennas arranged on the same circumference centering the microstrip antenna, and plural phase shifters. CONSTITUTION:A central printed circuit antenna #01 and print antennas #11-#14 on the same circumference keeping intervals are arranged on the surface of a dielectric substrate 1. When the satellite is found out by a mobile body first, uniform exciting phases are supplied to the peripheral printed circuit antennas #11-#14, and central antenna #01 is excited with the phase deviated by a constant quantity from those exciting phases. Thereby, since beam width can be extended, a time required from the discovery of the satellite can be shortened. Also, by applying mutual excitation with a negative phase by bi-secting the peripheral antennas #11-#14 when the satellite is traced, and shifting the phase of the phase shifter 3 in point of time one after another, a beam direction is rotated spirally centering a Z-axis perpendicular to the substrate 1. In such a way, conical scan tracing can be performed at high speed by the control of an electrical phase shifter.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a microstrip array antenna,
In particular, the present invention relates to a microwave band or sub-millimeter wave band microstrip array antenna mounted on a mobile station such as a car or a ship for satellite tracking.

(Prior Art) As is well known, various methods such as a monopulse method and a conical scan method are known as methods for tracking a satellite by a mobile station such as a car or a ship.

Among these, the monopulse method uses six antenna elements 6.6.6 for distinguishing the azimuth angle and the elevation angle, as shown in FIG. 4, for example. ... 6 are connected to the combining circuits 7a and 7b every three, but the output of each combining circuit (7a, 7b) is led to the hybrid circuit 8, where the Σ (sum) signal and Δ (difference)
This method tracks satellites by detecting signals.

In addition, in the conical scan method, the antenna beam is rotated in a conical shape, and the deviation of the antenna beam is found from the amplitude modulation component of the received signal obtained when the satellite is deviated from the center of the antenna beam.The angular error voltage indicating this deviation is The antenna is driven so that it disappears.

(Problem to be solved by the invention) However, the conventional monopulse tracking array antenna is
Because the signal system combines all array elements in phase, the radiation beam becomes sharp and it takes too long to find a satellite for the first time. The conical scan method also has a sharp radiation beam and a similar problem.

In addition, in the conical scan method, it is necessary to mechanically move the antenna slightly to perform detection, which requires a drive device to shift the beam, which increases the size of the device.Furthermore, since the beam is mechanically moved, tracking response There is also the problem that it is slow.

The present invention was made in view of such conventional problems, and its purpose is to facilitate initial acquisition of a satellite and speed up subsequent tracking of the satellite, thereby making it suitable as a satellite tracking antenna for mobile objects. The object of the present invention is to provide a microstrip array antenna.

(Means for Solving the Problems) In order to achieve the above object, the microstrip array antenna of the present invention has the following configuration.

That is, the microstrip array antenna of the present invention is
A microstrip antenna arranged on the surface of a dielectric substrate, comprising one microstrip antenna and a plurality of microstrips arranged at appropriate intervals on the same circumference centered on the one microstrip antenna. An antenna; A plurality of phase shifters provided on the back side of the dielectric substrate and connected to each of the microstrip antennas via the dielectric substrate; Controlling the amount of phase shift of the plurality of phase shifters. A device in which multiple microstrip antennas on the circumference are all excited in the same phase, and one microstrip antenna at the center is shifted by a predetermined phase amount from the excitation phase of the multiple microstrip antennas on the circumference. excitation with a phase that
Then, one microstrip antenna at the center is excited with a predetermined phase, and a plurality of microstrip antennas on the circumference are divided into two into a predetermined number of adjacent microstrip antenna groups, and each microstrip antenna in both groups is The strip antenna is excited with a phase shifted by a predetermined phase from the excitation phase of one microstrip antenna at the center, which has the same phase within the same group and an opposite phase between both groups, and also has an opposite phase between both groups. a control unit that sequentially changes the excitation mode between adjacent microstrip antennas in both groups in one direction over time while keeping the relationship and the number of antennas constituting the group constant;
It is characterized by having the following.

(Function) Next, the function of the microstrip array antenna of the present invention configured as described above will be explained.

When first finding a satellite from a moving object, a −-like excitation phase is applied to the microstrip antennas arranged on the circumference of the substrate, and the microstrip antenna in the center is shifted by a certain amount from the excitation phase. Excite in phase. As a result, the beam width becomes wider than the beam formed when −-like excitation phases are given to all the microstrip antennas, including the one in the center, without changing the beam direction. As a result, the permissible range for finding a satellite is expanded, and the time required to find a satellite is shortened.

In addition, when tracking a satellite, the excitation phase to the microstrip antenna at the center is kept constant, and the microstrip antennas on the circumference have the same phase within each group of microstrip antennas divided into two, but both The groups are excited in opposite phases, with a predetermined phase shift from the excitation phase of the central microstrip antenna, and the opposite phase relationship between both groups and the number of antennas constituting the group are maintained constant. As time passes, the excitation mode between adjacent microstrip antennas in both groups is sequentially changed in one direction.

As a result, the radiation beam from the circumferential microstrip antenna will rotate conically about an axis perpendicular to the substrate plane. Here, since phase shift control can be performed at high speed, conical scanning (ie, conical scanning) of the radiation beam can be performed at high speed. In this way, it is possible to speed up the tracking response in conical scan tracking.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a microstrip array antenna according to an embodiment of the present invention. In FIG. 1, one microstrip antenna (hereinafter referred to as
"Central printed antenna J) #01 and four printed antennas (#11. #12. #1
3° #14) is provided. Further, a grounding plate 2 is provided on the back surface of the dielectric substrate 1, and the back surface of each printed antenna is electrically connected to this grounding plate 2 via the dielectric substrate 1.

A phase shifter 3. is provided in one-to-one correspondence with each printed antenna. ... are provided on the back side of the dielectric substrate 1, avoiding the radiation surface in consideration of the influence of the radiation electromagnetic field.

That is, phase shifter 3. ... are connected to a predetermined portion on the back surface of the corresponding printed antenna via the dielectric substrate 1, and are also connected to the ground plate 2. As a result, each phase shifter connects the corresponding printed antenna to 2 points under the control of the control unit 4.
This will give the correct excitation phase.

The control unit 4 mainly performs excitation phase control during satellite capture and excitation phase control during satellite tracking, which will be described below with reference to FIGS. 2 and 3.

When capturing a satellite, for example, as shown in Figure 2 (a), the excitation phase of the central printed antenna #01 is set to 70°, and the peripheral printed antennas #11, #12, #13, #14 are set.
When the excitation phase of is Oo, the radiation pattern is as shown in Figure 2 (b
) as shown by the solid line. The broken line shows the case where the same excitation phase is given to five printed antennas, but it can be understood that the beam width becomes wider in the case according to the present invention. That is, 3 d from the level of maximum gain
The half-value angle indicating the beam width of B-down increases from θ'B to θB. Note that the maximum radiation direction remains unchanged and the left-right symmetry of the beam is maintained. In this way, by shifting the excitation phase of the central printed antenna #01 from the excitation phases of the surrounding printed antennas #11 to #14 by a certain amount, the half-width of the beam can be widened. Satellite acquisition becomes easier.

Next, when tracking after capturing a satellite, conical scan tracking can be performed as follows.
As shown in figure (a), the excitation phase of central printed antenna #01 is Oo, and among the peripheral printed antennas,
If the excitation phase of #13 and #14 is +10°, and the excitation phase of #11 and #12 is -10°, the radiation beam direction is Z perpendicular to the dielectric substrate 1, as shown in FIG. 3(b). Slightly tilted to the right from the axis, i.e. peripheral printed antenna #11.
#12 is tilted at an angle θ in direction 5. Next, the excitation phase of central printed antenna #01 remains fixed (0°) and the excitation phase of #13 and #12 of the peripheral printed antennas is increased by +10'.
, #11 and #14 are set to 110 degrees, the beam is slightly tilted from the Z-axis direction toward the peripheral printed antennas #11 and #14. In this way, the phase of phase shifter 3 is changed one after another. If the beam direction is shifted in time, the beam direction will rotate in a conical (more precisely, pyramidal) shape around the Z axis, so conical scan tracking can be performed at high speed by controlling the electrical phase shifter. become.

In this embodiment, in order to facilitate understanding, the number of peripheral printed antennas is four, but as is clear from the above description, any number may be used as long as they do not overlap with each other.

Further, in this embodiment, a circular patch antenna is illustrated, but it goes without saying that other printed antennas can be used in the same manner.

(Effects of the Invention) As explained above, according to the microstrip array antenna of the present invention, one microstrip antenna and a plurality of microstrips arranged on the same circumference around the microstrip antenna are arranged on a dielectric substrate. Antenna and
Since the central antenna and peripheral antennas can be excited with different phases, a beam with a wide half-value width can be formed without changing the beam direction. As a result, the permissible range when capturing satellites is widened, and the time required to find a satellite is shortened.

In addition, the peripheral antenna is divided into two parts and excited with opposite phases to each other.
In addition, we made it possible to scan the radiation beam in a conical manner.
Conical scan satellite tracking is possible.

At this time, conical scan tracking is performed not mechanically but by temporal control of the bias voltage to the phase shifter connected to the microstrip antenna, so a high-speed tracking response is possible.

Furthermore, since the device can be made smaller, there are various excellent effects such as being able to provide a tracking array antenna suitable for mounting on a mobile object for satellite communication.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of the configuration of the microstrip array antenna of the present invention, Fig. 2 is an explanatory diagram of excitation phase control during satellite acquisition, Fig. 3 is an explanatory diagram of excitation phase control during satellite tracking, and Fig. 4 is an explanatory diagram of excitation phase control during satellite tracking.
The figure is a conceptual diagram of a conventional microstrip array antenna. 1...Dielectric substrate, 2...Grounding plate,
3... Phase shifter, 4... Control section,
#01... Microstrip antenna (center printed antenna), #11 to #14... Microstrip antenna (peripheral printed antenna). Sashi Tai Kansai ↑ (a) Pura Shun - ° - Ten no Pherson Torite length scolding - or excitation in the T field, shakuchi bankata shiba, body size no Vtar J (b) 0 @ 70 @ O6 is also 70 Street, Fff Andete's mff1lJ prisoner (b) ne4kichi°my70s) SoubuaL, A7Lthio's ministry 1Azeljtato / eye $ 2 Ward (b) Δ Σ Zashihigashi no microstrip are 4 asotega f) 1 house in line (Mojino\゛rus 7 tails) $4 ward

Claims (1)

[Claims] A microstrip antenna arranged on the surface of a dielectric substrate, comprising one microstrip antenna and a plurality of microstrips arranged at appropriate intervals on the same circumference centered on the one microstrip antenna. an antenna; a plurality of phase shifters provided on the back side of the dielectric substrate and connected to each of the microstrip antennas via the dielectric substrate; controlling the amount of phase shift of the plurality of phase shifters; A device in which multiple microstrip antennas on the circumference are all excited in the same phase, and one microstrip antenna at the center is shifted by a predetermined phase amount from the excitation phase of the multiple microstrip antennas on the circumference. Exciting one microstrip antenna at the center with a predetermined phase, and dividing a plurality of microstrip antennas on the circumference into two groups into a predetermined number of adjacent microstrip antenna groups. and exciting each microstrip antenna in both groups with a phase shifted by a predetermined phase amount from the excitation phase of the one microstrip antenna at the center, which has the same phase within the same group and has an opposite phase between both groups. , a control unit that sequentially changes the excitation mode between adjacent microstrip antennas in both groups in one direction over time while keeping the antiphase relationship between the two groups and the number of antennas constituting the group constant; A microstrip array antenna comprising: and;