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Dielectric Resonator Filter

dielectric resonator
transformation
Gunn diode
resonant microstrip

Figure 1: schematic construction of a gunn-oscillator in stripline technology

dielectric resonator
transformation
Gunn diode
resonant microstrip

Figure 1: schematic construction of a gunn-oscillator in stripline technology

dielectric resonator
transformation
Gunn diode
resonant microstrip

Figure 1: schematic construction of a gunn-oscillator in stripline technology

Dielectric Resonator Filter

The stripline technology is predominant today. But there aren't available resonant circuits of high quality here, because of larger line losses in comparison with the coaxial and waveguide technology, however. Therefore dielectric resonator filters are used often. The accompanying figure shows a gunn-oscillator in stripline technology with a dielectric resonator filter.

These cylindrical resonators are made of dielectric material (Barium-Titanat-Ceramic: a mixture of barium oxide and titanium dioxide) of a relative permittivity of 35...40. The H01- resonance preferably is made use of. The dielectric resonator filters is coupled to the microstripline magnetically. One can design with this technology oscillator applications in a wide range with a low noise figure and precise temperature coefficients.

A very high Q is typical available e.g. Q0 ≈ 10.000 at f0 = 4 GHz.
A typical application of dielectric resonator filters is the local oscillator in the Low-Noise Converters in the receiving plants for the satellites television reception.

Figure 2: dielectric resonator in an oscillator circuit used in a low-noise converter

Figure 2: dielectric resonator in an oscillator circuit used in a low-noise converter