Filtering device and related wireless communication receiver
A filtering device includes an isolation substrate including a first plane and a second plane, a micro-strip line deposited on the first plane of the isolation substrate for transmitting signals, and a ground metal layer deposited on the second plane of the isolation substrate for providing grounding. A meander-shaped resonating cavity is formed in an area of the ground metal layer corresponding to an area of the micro-strip line, for generating a rejection band on the micro-strip line.
1. A filtering device comprising:
an isolation substrate comprising a first plane and a second plane;
a micro-strip line, deposited on the first plane of the isolation substrate, for transmitting signals; and
a ground metal layer, deposited on the second plane of the isolation substrate, for providing grounding;
wherein a meander-shaped resonating cavity is formed in an area of the ground metal layer confined within an area of the micro-strip line, for generating a rejection band on the micro-strip line.
2. The filtering device of claim 1 , wherein an interval of the meander-shaped resonating cavity is direct proportional to a bandwidth of the rejection band.
3. The filtering device of claim 1 , wherein an interval of the meander-shaped resonating cavity is inverse proportional to a resonant point transmittal coefficient of the filtering device.
4. The filtering device of claim 1 , wherein a total length of the meander-shaped resonating cavity corresponds to a center frequency of the rejection band.
5. The filtering device of claim 1 , wherein the meander-shaped resonating cavity is formed in the ground metal layer by an etching process.
6. The filtering device of claim 1 further comprising a housing covering the ground metal layer.
7. The filtering device of claim 6 further comprising a draght space formed in an area of the housing corresponding to an area of the meander-shaped resonating cavity.
8. The filtering device of claim 7 , wherein an area of the draght space projected on the second plane of the isolation substrate is larger than an area of the meander-shaped resonating cavity.
9. The filtering device of claim 7 , wherein a depth of the draght space is inverse proportional to a center frequency of the rejection band.
10. The filtering device of claim 1 further comprising a tuning screw set in the isolation substrate, for adjusting a distance between the tuning screw and the micro-strip line, to adjust a center frequency of the rejection band.
11. A wireless communication receiver comprising:
an antenna, for receiving a wireless signal;
a wave guide, coupled to the antenna, for enhancing an electric wave of a certain frequency band in the wireless signal;
a frequency down converter, for reducing a frequency of the wireless signal, to output an IF (intermediate-frequency) signal;
a baseband processor, for processing the IF signal; and
a filtering device comprising:
an isolation substrate comprising a first plane and a second plane;
a micro-strip line, deposited on the first plane of the isolation substrate, for transmitting signals; and
a ground metal layer, deposited on the second plane of the isolation substrate, for providing grounding;
wherein a meander-shaped resonating cavity is formed in an area of the ground metal layer confined within an area of the micro-strip line, for generating a rejection band on the micro-strip line.
12. The wireless communication receiver of claim 11 , wherein an interval of the meander-shaped resonating cavity is direct proportional to a bandwidth of the rejection band.
13. The wireless communication receiver of claim 11 , wherein an interval of the meander-shaped resonating cavity is inverse proportional to a resonant point transmittal coefficient of the filtering device.
14. The wireless communication receiver of claim 11 , wherein a total length of the meander-shaped resonating cavity corresponds to a center frequency of the rejection band.
15. The wireless communication receiver of claim 11 , wherein the meander-shaped resonating cavity is formed in the ground metal layer by an etching process.
16. The wireless communication receiver of claim 11 further comprising a housing covering the ground metal layer.
17. The wireless communication receiver of claim 16 further comprising a draght space formed in an area of the housing corresponding to an area of the meander-shaped resonating cavity.
18. The wireless communication receiver of claim 17 , wherein an area of the draght space projected on the second plane of the isolation substrate is larger than an area of the meander-shaped resonating cavity.
19. The wireless communication receiver of claim 17 , wherein a depth of the draght space is inverse proportional to a center frequency of the rejection band.
20. The wireless communication receiver of claim 11 further comprising a tuning screw set in the isolation substrate, for adjusting a distance between the tuning screw and the micro-strip line, to adjust a center frequency of the rejection band.