JPS60123106A - Frequency trimming method - Google Patents

Abstract

PURPOSE:To trim a frequency continuously while monitoring a resonance frequency with an oscillating circuit by trimming the frequency while measuring directly the resonance frequency in on-line. CONSTITUTION:If phase conditions which cause proper positive feedback oscillation are attained by a variable phase shifter 8, the frequency of the oscillating circuit is equal to a natural resonance frequency of a dielectric resonator 1. The oscillated frequency signal is led to a frequency counter 10, and the counted value is compared with a prescribed value which is stored preliminarily in a computer 11. If the oscillated frequency is lower as the result of this comparison, abrasive powder 13 is jetted to one plane of the dielectric resonator 1 from a nozzle 9 through a jet controller 12 on a basis of an indication of the computer 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dielectric material for use in microwave local oscillation sources, filters, etc., which require extremely high precision in frequency setting value and stability. Concerning improvements in frequency trimming methods for body resonators.

(Prior art) Microwave resonant elements are required to be small and have an aspect ratio of 44.
The implementation has shifted from conventional cavity resonators to dielectric resonators. In dielectric resonators, the Q and temperature coefficient of circuits have been improved through improvements in the constituent materials and manufacturing methods, and the range of applications has expanded.

The resonant frequency of a dielectric resonator is determined by the dielectric constant of the constituent materials and the shape of the resonator, that is, the physical dimensions, and the accuracy of the frequency also depends on the accuracy of the physical dimensions. However, the frequency accuracy required for the resonator is 0.
However, the accuracy obtained after sintering a dielectric resonator exceeds 1% even under conditions where materials and manufacturing methods are controlled as much as possible.
Conventionally, the required precision has been achieved by polishing the dielectric surface after sintering. This polishing υ0 process generally uses an abrasive material with a diameter of +100 mm or more.The resonance frequency is measured using a special measuring jig, and the process of removing it from the measuring jig and polishing is repeated frequently until the desired value is reached. I was forced to do that. Therefore, in the manufacturing process of the dielectric resonant element, the process of adjusting the resonant frequency 11t requires a large amount of time, and there has been a call for improvement in terms of production costs.

(Object of the Invention) The object of the present invention is to provide a computer and a frequency counter in addition to an injection means for injecting polishing powder, and perform frequency trimming while directly measuring the resonance frequency online. The object of the present invention is to provide a frequency trimming method for a dielectric resonator that is inexpensive and has high frequency setting accuracy.

(Structure of the invention) The frequency trimming method according to the present invention uses an oscillator circuit.

It is realized by being equipped with an injection means, a computer, and a one-frequency counter.

The oscillation circuit includes a microwave dielectric resonant element to perform frequency trimming, and is a closed loop configured by an amplifier and a variable phase shifter.

The injection means performs frequency trimming of the microwave dielectric resonant element, and includes an injection controller for injecting the polishing powder as and where necessary and only as necessary;
It includes a nozzle, a nozzle position controller, etc.

The computer is responsible for controlling the injection means on-line.

The frequency counter detects the end of frequency trimming based on the oscillation frequency of the oscillation circuit, and is used to record the oscillation frequency and provide it to the computer as data.

In the present invention, the output of an oscillation circuit tuned to the resonant frequency of the microwave dielectric resonator is counted by a frequency counter, and the data obtained by counting is compared with a desired value inside a computer, and the nozzle is This was achieved by spraying polishing powder onto the microwave chi-electric resonator while it was moving until the data reached the desired value.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration for realizing an embodiment of the frequency trimming method according to the present invention. In Figure 1, 1 is a dielectric resonator, 2 and 6-digit coupling parts, 4 are amplifiers, 5 and 6 are variable attenuators, 7 is a signal distributor, 8 is a variable phase shifter, 9-digit nozzles, and 1o is a frequency Counter, 11 is computer, 1
2 is an injection controller, 16 is a grinding powder, and 14 is a nozzle position controller.

An oscillation circuit is constructed by coupling an amplifier 4, variable attenuators 5, 6, @outer distributor 7, and variable phase shifter 8 to the dielectric resonator 1 via electrical coupling parts 2 and 6. do. In this embodiment, a part of the output signal of the amplifier 4 is used again as an input signal to the amplifier 40 via the dielectric resonator 1, so that the circuit becomes a so-called feedback oscillation circuit. Therefore, when the phase condition for causing appropriate positive feedback oscillation is obtained by the variable phase shifter 8, the frequency of the oscillation circuit becomes equal to the natural resonant frequency of the dielectric resonator 1. A portion of this oscillation frequency signal is sent to the frequency counter 1 by the signal distributor 7.
0, the count value of the generator output frequency is compared with a desired value previously stored in the computer 11. (As a result of -, if the oscillation frequency is low, the polishing powder 16 of alumina etc. of +500 mesosh or more is
1, the liquid is injected from the nozzle 9 onto one plane of the dielectric resonator 1 via the injection controller 12.

At this time, the injected portion of the dielectric resonator 1 is physically polished, and its oscillation frequency changes to a high value. The frequency trimming conditions in this step, especially the injection time of the polishing powder 16, can be optimally controlled by a working condition program stored in the computer 11 in advance based on the difference between the oscillation frequency' and a desired value. In addition, if the polishing powder 16 (i-) is locally injected into the dielectric resonator 1, the electromagnetic field distribution inside the dielectric resonator 1 may be disturbed, leading to a decrease in Q. Therefore,
By moving the re-nozzle 9 within one plane of the dielectric resonator 1 using the nozzle position controller 14, uniform height grinding can be performed. By setting the diameter of the dielectric resonator 1 as the maximum value and storing that value in the computer 11 in advance, it is possible to give a movement instruction to the nozzle position controller 14.

In this embodiment, a positive feedback type oscillation circuit is configured for the dielectric resonator 1, but a reflection type, -! The circuit format can be arbitrarily selected by configuring an oscillator tuned to a pass-through dielectric resonator.

(Effects of the Invention) As explained above, the present invention includes a computer and a frequency counter in addition to an injection means for injecting abrasive powder, and performs frequency trimming while directly measuring the resonance frequency online. For frequency trimming of dielectric resonators, which require accurate frequency setting, polishing and resonant frequency measurement are repeated alternately, and the resonant frequency is monitored by an oscillation circuit, making it possible to continuously trim the frequency from the force. This method has the advantage of being able to exhibit a time-saving effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the trimming method according to the present invention. 1. Dielectric resonator 2.6... Coupling section 4... Amplifier 5.6... Variable attenuator 7... Signal distributor 8... Variable phase shifter 91111-Nozzle 10... - Frequency counter 11... Computer 1211... Injection controller 13... Polishing powder 14-@, Nozzle position controller Patent applicant
NEC Co., Ltd. Agent Patent Attorney Hisashi Inoro

Claims (1)

[Claims] A closed-loop oscillation circuit including a microwave dielectric resonant element to be subjected to frequency trimming and configured by an amplifier and a variable phase shifter, and a polishing circuit to perform frequency trimming of the microwave dielectric resonator element. An injection controller that allows you to spray powder as needed, where you need it, and in the amount you need. An injection means including a nozzle, a nozzle position controller, etc., a computer for controlling the injection means online, and an oscillation frequency of the oscillation circuit to detect the end of the frequency trimming. and a frequency counter for providing data to a computer, the output of the oscillation circuit tuned to the resonant frequency of the microwave dielectric resonator is counted by the frequency counter, and the data obtained by the counting is provided. is compared with a desired value in the computer, and the polishing powder is sprayed onto the microwave dielectric resonator while moving the nozzle until the data reaches the desired value. A frequency trimming method characterized by the following.