一、Characteristics
The surface acoustic wave filter (SAW filter for short) is used to suppress high order harmonics, image information, emission leakage signal and all kinds of parasitic clutter interference. The advantages of SAW filters are high quality factor, narrow bandwidth selection, low insertion loss, high signal transmission efficiency, simpler installation than traditional LC filters, and strong stability over a wide range of operating temperatures. The amplitude-frequency and phase-frequency characteristics can be filtered with any desired accuracy. The disadvantages of SAW filter are that the insertion loss is larger than that of LC resonant circuit, the bandwidth is too narrow (tens of KHZ), the sensitivity is limited, and the frequency range is limited.
The surface acoustic wave filter (SAW filter for short) for the Beidou band of 1575.42MHz can replace the LC resonant circuit for interstage coupling and filtering. The 1575.42MHz surface acoustic wave filter is mainly used for signal processing and frequency selection in satellite navigation equipment. It can filter signals in a specific frequency range, suppress unwanted frequency components, and retain useful frequency signals. Compared with the traditional ceramic resonator, the installation is simpler, the volume is smaller, the price is cheap, and the device integration is high.

1575.42MHz surface acoustic wave filter
| Item | Minimum | Minimum | Maximum | Maximum |
| Center Frequency |
| 1575.42 |
| MHz |
| Insertion Loss (min) | - | 1.0 | 2.0 | dB |
Insertion Loss (1559.10~1591.74MHz)
| - | 2.0 | 3.0 | dB |
Ripple in BW (1559.10~1591.74MHz) | - | 1.0 | 1.5 | dB |
Ripple in Group delay (1559.10~1591.74MHz) | - | 15.0 | 35.0 | ns |
Input V.S.W.R (1559.10~1591.74MHz) | - | 1.6 : 1 | 2.0 : 1 | - |
Output V.S.W.R (1559.10~1591.74MHz) | - | 1.6 : 1 | 2.0 : 1 | - |
Attenuation |
DC~1500.00 MHz | 30.0 | 25.0 | - | dB |
1610.0~1650.0 MHz
| 30.0 | 32.0 | - | dB |
1650.0~3000.0 MHz
| 25.0 | 38.0 | - | dB |
| Operating temperature | -40 | - | +85 | ℃ |
| Encapsulation form | SMD 3030 |
二、Package Dimension

3030 SAW resonator
| Pin | Configuration |
| 2 | Input |
| 5 | Output |
| 1、3、4、6 | Case Gorund |
三、Circuit diagram

saw filter circuit diagram
四、Typical Frequency Response
Narrow-band response Broadband response measured

Time delay ripple and S11 V.S.W.R Time delay ripple and S22 V.S.W.R
五、Application & attention
Because the 3030 package of the surface acoustic wave filter is easier to install, smaller size, cheap, so it is widely used in wireless communication systems in the field of frequency band selection, frequency conversion, RF front-end and baseband processing. When used, the welding temperature should not be too high, and the time should not be too long. If reflow welding is used, reference temperature is recommended, and wave crest welding 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 SAW filter, Beidou band filter, 1268.52MHz surface acoustic wave filter, 1575.42MHz surface acoustic wave filter and SAW resonators and other frequency microwave electronic components.