一、Characteristics
The main function of the LTCC bandpass filter is to allow signals in a specific frequency range to pass, while suppressing signals above and below that frequency range, thereby controlling signals in other frequency ranges. The working principle of LTCC bandpass filter is based on the resonant effect and frequency selectivity of the material, when the frequency of the input signal is close to the resonant frequency of the filter, the response of the filter will be enhanced, so that the signal in the frequency range can pass through; When the frequency deviates from the resonant frequency, the response of the filter will be relatively reduced, and unwanted low and high frequency signals can be filtered out.
LTCC bandpass filter (dielectric bandpass filter) has excellent high frequency, high speed transmission and wide passband characteristics, can improve the quality factor of the circuit, input/output 50Ω impedance matching (75Ω needs special description), flexible design, high integration, easy to cascade use, high temperature resistance, light weight, small size, Good consistency, short production cycle, low cost, easy welding, stable and reliable performance in the full temperature range, and meet the requirements of military working environment (-55℃ ~ +85℃).
LTCC bandpass filter
二、Electrical Characteristics
LTCC bandpass filter model and parameter table
|
Part No
| Frequency（MHz） | Insertion loss（dB） | V.S.W.R | Size（mm） | SPEC |
| LF18B1915H1008-N276 | 1805 -- 2025 | ≤ 1.5 | ≤ 2.0 | 1.6 * 0.8 * 0.7 |  |
| LF18B1915H1008-N257 | 1805 -- 2025 | ≤ 2.3 | ≤ 2.0 | 1.6 * 0.8 * 0.7 | |
| LF18B1915H1008-N257/C | 1880 -- 2025 | ≤ 2.1 | ≥10 dB | 1.6 * 0.8 * 0.7 | |
| LF21B2450H61-N175/K | 2400 -- 2500 | ≤ 1.5 | ≤ 2.0 | 2.0 * 1.25 * 0.95 | |
| LF18B2450P57-N174/T | 2400 -- 2500 | ≤ 1.7 | ≤ 2.0 | 1.6 * 0.8 * 0.6 | |
| LF18B2450P57-N174/K | 2400 -- 2500 | ≤ 1.5 | ≤ 2.0 | 1.6 * 0.8 * 0.6 | |
| LF22B2450P47-N21/L | 2400 -- 2500 | ≤ 1.2 | ≤ 2.0 | 2.5 * 2.0 * 1.2 | |
| LF18B3750H0908-N271 | 3300 -- 4200 | ≤ 2.0 | ≤ 2.0 | 1.6 * 0.8 * 0.35 | |
| LF15B3750H0908-N270 | 3300 -- 4200 | ≤ 2.0 | ≥14 dB | 1.0 * 0.5 * 0.38 | |
| LF21B3342H98-N255 | 3300 -- 4200 | ≤ 2.0 / ≤ 2.0 / ≤ 1.5 | ≤ 2.0 | 2.0 * 1.25 * 0.7 | |
| LF18B5425H0906-N266 | 3900 -- 5950 | ≤ 0.85 | ≤ 2.1 | 1.6 * 0.8 * 0.65 | |
| LF21B4450H86-N253 | 4400 -- 5000 | ≤ 0.9 | ≥10 dB | 1.6 * 0.8 * 0.6 | |
| LF18B5370H95-N217/K | 4900 -- 5840 | ≤ 1.5 | ≤ 2.0 | 1.6 * 0.8 * 0.6 | |
| LF18B5550H95-N264/T | 5150 -- 5950 | ≤ 2.0 / ≤ 1.6 / ≤ 2.0 | ≤ 2.0 | 2.0 * 1.25 * 0.7 | |
| LF18B5550H95-N264 | 5150 -- 5950 | ≤ 1.2 | ≥10 dB | 1.6 * 0.8 * 0.6 | |
| Note: Due to many product models, only some representative models are listed in the table |
三、Application & attention
LTCC bandpass filter can realize accurate signal processing, in the signal processing, signal detection, data processing, signal analysis and other fields have a wide range of applications, suitable for radio, broadcasting, radar, navigation, electronic reactance, RF circuit and other occasions. In use, the input/output outlet can be used interchangeably, but pay attention to the grounding end is well grounded, otherwise it will affect the out-of-band suppression and flatness indicators, the welding temperature can not be too high, the time can not be too long. If reflow welding is used, the recommended temperature is recommended, and wave soldering is not recommended. Products should be stored in the ambient temperature of -10℃~40℃, relative humidity is not more than 80%, the surrounding environment is not acidic, alkaline and other harmful gases in the warehouse. Do not soak when cleaning, it is recommended to wipe with alcohol.
The company has a variety of sizes of LTCC bandpass filter (ceramic bandpass filter) for users to choose, flexible design, support customization (input/output form and shape size can be designed according to user requirements). LTCC high-pass filter, LTCC low-pass filter, LTCC band-stop filter, LTCC band-pass filter can be customized. Because the indicators of microwave components are related to each other and sound to each other, the user needs to clearly state the indicator requirements before customization. Once the product is made, it cannot be changed. If there are indicators that exceed the physical limit of the material itself, the best indicators can be achieved through negotiation between the two parties.
