一、Characteristics
Switching filter is a new type of device composed of cavity filter (can also use microstrip/strip line filter, medium filter, cavity filter, LC filter) or microstrip filter and microfilter switch together, is an important component of superheterodyne receiver, its component performance directly affects the whole system noise factor, spectrum purity and other performance indicators. In the switching filter, the filter uses tap type input and output structure and interfinger form, which has small in-band loss, high out-of-band suppression, small size, compact structure, fast channel switching speed (ns level switching speed), small amplitude difference between channels, low insertion loss, input/output 50Ω impedance matching, easy to cascade use; The performance is stable and reliable in the full temperature range, and meets the requirements of military working environment (-55℃+85℃).
Switching filter
二、Model & Electrical characteristics
Switching filter (microstrip/linear switching filter) main parameter table
| Switching filter (microstrip/linear switching filter) main parameter table表 |
| No | Parameter | Argument |
| 1 | Operating frequency | 960~1224 MHz |
| 2 | 1dB Passband bandwidth | ≥ 264 MHz |
| 3 | Passband gain | 3 ± 0.8 dB |
| 4 | Output power 1dB compression point | ≥ 13 dBm |
| 5 | Divided into 8 segments of frequency selection filter F1-F8, each segment of filter bandwidth | ≥ 33 MHz |
| 6 | 45 MHz suppression outside the F1-F8 belt | ≥ 30 dBc |
| 7 | 100 MHz suppression outside the F1-F8 belt | ≥ 55 dBc |
| 8 | Input/Output V.S.W.R | ≤ 1.7 |
| 9 | Group delay of filter | ≤ 40 ns |
| 10 | Group delay Ripple | ≤ 20 ns |
| 11 | Supply voltage | + 5 V |
| 12 | Channel selection signal | Three-bit TTL parallel control code |
| Note: Due to many product models, only some representative models are listed in the table |
Switching filter (microstrip/linear switching filter) model and parameter list
| Metal cavity filter type and parameter table |
| Frequency | BW(MHz) | Attenuation (dBc)min | Insertion loss (dB)max | Ripple (dB)max | Frequency conversion speed (s)max | Input/output V.S.W.R (max) | Control mode | Size(mm) |
| L Band (4R) | Dot frequency /BW3dB≥145 | 75@fo±100MHz | 7.0 | 1.2 | 1 | 22 | TTLSignal | 103*75*14 |
L Band (5R) | BW1dB≥100 | 55@fo-130MHz 73@fo+230MHz | 6.0 | 1.0 | 0.25 | 2 | TTL Control signal | 60*60*12 |
L Band (6R) | BW0.5dB≥±10 | 20@fo±30MHz 50@fo±60MHz 70@fo±100MHz | 5.5 | 1.0 | 1.0 | 1.5 | LVTTL Signal | 62*80*20 |
L Band (8R) | BW0.5dB≥±22 | 85@fo±115MHz | 5.5 | 0.5 | 1.0 | 1.5 | TTL Signal | 75*32*16 |
L Band (8R) | BW1dB≥33±2 | 30@fo±61.5MHz 55@fo±116.5MHz | 3 ± 0.5 | 1.0 | 0.2 | 1.7 | TTL Signal | 75*50*14 |
L Band (11R) | BW1dB>25 | 60dBc@fn±40MHz | 8.0 | 2.0 | 0.3 | 2 | TTL Control signal | 85*85*16.5 |
L Band (21R) | BW0.5dB≥26.7 | 40@fn±45MHz | 7.0 | 0.5 | 1.0 | 2 | TTL Control signal | 130*70*15 |
L Band (22R) | BW1.2dB≥13.3 | 40@fo±35MHz | 9.0 | 1.2 | 0.9 | 1.7 | TTL Signal | 190*136*28 |
C Band (2R) | BW3dB≥±10 | 25@fo±30MHz 55@fo±60MHz 75@fo±100MHz | 6.0 | 1.0 | 1.0 | 1.5 | LVTTL Signal | 90*45*12 |
C Ban (8R) | BW3dB≥±10 | 25@fo±30MHz 55@fo±60MHz 75@fo±100MHz | 6.0 | 1.0 | 1.0 | 1.5 | LVTTL Signal | 90*45*12 |
C Ban (10R) | BW0.5dB≥26.7 | 60dBc@fn±45MHz | 5.5 | 1.0 | 2.0 | 2.0 | LVTTL Signal | 80*40*16 |
| Note: The working frequency band is from L-band to K-band, and the number of switching channels can be customized according to user needs* Due to the large number of product models, only some representative models are listed in the table |
三、Application & attention
The operating frequency of the switching filter is from L-band to K-band, and the number of switching routes can be customized according to customer needs. The filter in the switching filter can adopt strip line/microstrip filter, ceramic filter, LC filter, cavity filter, etc. The switching filter has the advantages of fast switching time (ns switching speed), small amplitude difference between channels, and maximum operating frequency up to K band. Products are widely used in RF radio frequency circuit, electronic countermeasures, aviation, aerospace, radar, satellite communication, mobile communication and other communication systems.
This product is a highly customized product, the number of switches and other indicators can be customized, the user needs to confirm the parameter requirements with our technical staff by phone or email before customization. The company can customize the switching filter, microstrip switching filter, strip line switching filter, cavity switching filter, dielectric switching filter, ceramic switching filter. The user puts forward reasonable requirements, and the parameters beyond the physical limit of the material can be negotiated to achieve the best indicators.
