Input
attenuator
Mixer
Intermediate
frequency
filter
PC
Logarithmic
amplifier
Circuit
encoder
Signal
processor
swip-
generator
Input
Figure 1.2. Spectrum analyzer
Firstly, the method of indirect measurement of the frequency with known
analogue control current of YIG-resonator or control code in digital form [3]. Despite
the good linearity of the current-frequency control dependency, it is difficult to obtain
the error of determining the frequency less than 2 %.
Secondly, modern way is to build a swip-generator based on the generator with
YIG-resonator. Such generator build in the form of a range frequency synthesizer. The
frequency of its initial oscillation set up with high precision via the digital code from
the microcontroller [4]. The disadvantage of this method is the complexity of the
implementation and the fact that the phase noise of the swip- generator increases
in comparison with the potential opportunities not covered by the bundles of the inverse
control of the generator on the YIG-resonator.
Proposed frequency meter is good by its precision, simplicity and ability to work
together with the non-covered inverse regulation of the RF generator based on a YIG-
resonator with low phase noise.
2. Yig-resonators. The work of YIG resonators base on the phenomenon of
ferromagnetic resonance in ferrite single crystals. From other ferrites, which also reveal
resonance phenomena, ferrite YIG is different by small losses, which explains their
high Q-factor. The frequency of resonance with high linearity is proportional to the
external magnetic field, which allows reconstruct the resonator.
The resonating element usually makes in the form of a sphere (sometimes a disk)
with a diameter of about 0.5 mm, with a well-treated surface. For using as a filter
connection with a resonator is carried out by two mutually perpendicular inductive
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