Liquid cooled high-frequency filter
View Patent ↗The invention refers to a high-frequency filter ( 1 ), comprising a filter housing ( 2 ), the filter housing ( 2 ) having at least one cover element ( 2 a ) with at least one resonator ( 5, 6, 7, 8, 9, 10, 11, 12 ) positioned therein and at least one signal input ( 3 ), through which a high frequency signal is coupled to the first resonator ( 5 ) and a signal output ( 4 ), through which a high frequency signal is coupled from the last resonator ( 10 ) to downstream appliances wherein the cover element ( 2 a ) is made from a thermally conductive material and the resonator ( 5, 6, 7, 8, 9, 10, 11, 12 ) is arranged to be in thermal connection with the cover element ( 2 a ). The cover element ( 2 a ) has at least one recess ( 23 ) arranged therein, along with a liquid coolant is guided in order to absorb thermal energy resulting from feeding the high frequency signal to the resonator ( 5, 6, 7, 8, 9, 10, 11, 12 ). The liquid cooled high-frequency filter according to the invention allows for an increased input power while retaining the physical dimensions of the filter assembly constant, thus, omitting resonator instabilities due to the development of higher TEM modes.
1. High-frequency filter comprising a filter housing, the filter housing having at least one cover element with a resonator positioned therein;
at least one signal input, through which a high frequency signal is coupled to the resonator and a signal output, through which a high frequency signal is coupled from the resonator to downstream appliances;
wherein the cover element is made from a thermally conductive material and the resonator is arranged to be in thermal connection with the cover element; and wherein:
the cover element has at least one recess arranged therein, along which a liquid coolant is guided in order to absorb thermal energy resulting from feeding the high frequency signal to the resonator.
2. High frequency filter according to claim 1 , wherein:
at least one tubing element, through which the liquid coolant flows, is positioned inside the recess of the cover element, whereby the tubing element is in thermal connection with the material of the cover element.
3. High frequency filter according to claim 2 wherein:
the at least one tubing element and/or the cover element is made from a material selected from a group comprising aluminum, zinc, copper, silver, gold, brass, bronze, alloys thereof or any other metals or alloys having a sufficiently high thermal conductivity, thermally conductive polymers, as well as combinations thereof.
4. High frequency filter according to claim 2 , wherein:
the at least one tubing element is made from a different material than the cover element and preferably from a material having a higher thermal conductivity than the cover element.
5. High frequency filter according to claim 1 , wherein:
the recess of the cover element is at least partially covered with at least one closing element, whereby the closing element is fixed to the cover element by a bonding material.
6. High frequency filter according to claim 1 , wherein:
at least one liquid cooling inlet and at least one liquid cooling outlet is provided through which a liquid coolant is applied to and drained from, respectively.
7. High frequency filter according to claim 6 , wherein
the inlet and/or outlet comprises valve means, preventing liquid coolant to leak in case the inlet and/or outlet is incorrectly connected or disconnected from a cooling liquid source or drain, respectively.
8. High frequency filter according to claim 1 , wherein
the filter housing comprises at least one resonator cavity, which is associated with said resonator to form a cavity resonator.
9. High frequency filter according to claim 1 , wherein:
the resonator is tunable, preferably tunable from 650 MHz to 700 MHz, more preferably tunable from 600 MHz to 750 MHz, yet more preferably tunable from 550 MHz to 800 MHz, most preferably tunable from 500 MHz to 850 MHz and particularly preferably tunable from 470 MHz to 862 MHz.
10. High frequency filter according to claim 1 , including:
multiple cavity resonators, inductive and/or capacitive coupling means are provided in order to couple multiple cavity resonators, the coupling means having an electrical length of λ/4.
11. High frequency filter according to claim 10 , wherein:
a serial arrangement of multiple cavity resonators, particularly bandpass cavity resonators is coupled by said inductive and/or capacitive coupling means, the arrangement having preferably 3, more preferably 4, most preferably 5, particularly preferably 6 or 8 or more resonators.
12. High frequency filter according to claim 11 , wherein:
a cross coupling of at least two of said cavity resonators, which are not coupled by said serial coupling, preferably the first and last cavity resonator, and most preferably the second and penultimate cavity resonator.
13. High frequency filter according to claim 10 , wherein:
at least one notch cavity resonator, which is coupled to a bandpass cavity resonator, and most preferably two notch cavity resonators, which are coupled to the first and last cavity resonators or to the second and penultimate cavity resonators.
14. Use of a high frequency filter according to claim 1 in a bandpass filter and/or a band-stop filter.