Production method for chip-form film-forming component
A description is given of a high frequency filter comprising microstrips. The filter comprises at least two resonators ( 16, 18 ) which each have, as frequency-determining elements, a first straight microstrip section ( 28 ) and a second straight microstrip section ( 30 ), which are parallel next to each other, and also a capacitor assembly ( 22 ). In each resonator the capacitor assembly is connected between first ends of the microstrip sections and each resonator is exclusively connected to ground at the second ends of the microstrip sections. In each resonator ( 16, 18 ) the sum of the two microstrip sections acts as inductive lement. The resonators ( 16, 18 ) therefore act in the same manner as a resonator having a single microstrip, the length of which corresponds essentially to the sum of the lengths of the first microstrip section ( 28 ) and the second microstrip section ( 30 ). This construction of a filter allows a shorter design compared to conventional filter structures.
1. A filter circuit comprising
an input and an output and
first and second resonators, one of which is coupled to the input and the other of which is coupled to the output,
wherein each resonator has, as frequency determining elements, a first straight microstrip section, a second straight microstrip section and a capacitor assembly,
wherein, in each resonator, the capacitor assembly is connected between first ends of the microstrip sections, and second ends of the microstrip sections are connected to ground,
and wherein the first and second microstrip sections in each resonator are arranged in parallel next to one another,
and wherein one of the microstrip sections of the first resonators is electromagnetically coupled to at least one of the microstrip sections of the second resonator by the microstrip sections of the resonators being arranged in parallel next to one another and at a distance apart.
2. A filter as claimed in claim 1 , in which the capacitor assembly of each resonator comprises at least one variable capacitor.
3. A filter as claimed in claim 2 , in which the capacitor assembly of each resonator comprises a series circuit of a fixed capacitor and the at least one variable capacitor.
4. A filter as claimed in claim 1 , in which the capacitor assembly of each resonator comprises a capacitance diode which is connected to a variable voltage via a high impedance resistor.
5. A filter as claimed in claim 1 , in which the first and second microstrip sections in each resonator have the same length.
6. A filter as claimed in claim 1 , in which one of the microstrip sections of the first resonators coupled exclusively electromagnetically to one of the microstrip sections of the second resonator.
7. A filter as claimed in claim 1 , in which between the input and the output there is a filter response of an order that corresponds to half the number of microstrip sections of the resonators.
8. A filter as claimed in claim 1 , in which the microstrip sections are attached to a front side of an insulating substrate, in which a conductive layer on the rear side is connected to ground, wherein the first and second microstrip sections each have at their second end a through-connection to the rear side of the substrate.
9. A filter as claimed in claim 1 , in which the input is coupled to the first resonator,
wherein the input is connected to a coupling microstrip which runs at right angles to the microstrip sections of the resonators,
and wherein the coupling microstrip intersects the first microstrip section of the first resonator.
10. A filter as claimed in claim 1 , in which the input is coupled to the first resonator,
wherein the input is connected to a first coupling microstrip which runs at right angles to the microstrip sections of the first resonator,
and wherein the first coupling microstrip is connected to a second coupling microstrip which runs in parallel next to and is electromagnetically coupled to the first microstrip section of the first resonator.