L-Band Low Pass Filter
Types of L-Band Low Pass Filter
L band is the frequency band from 1GHz to 2GHz. There are many communication systems utilizing this band of frequencies. The GPS (global positioning systems) is one such system. L-Band is also commonly used in Asia for satellite communications. A small part of the L-Band spectrum (1.3-1.7GHz) is used by Inmarsat for satellite communications.
L-Band components are also easily available and this helps to make L-Band satellite equipment cheaper and less difficult to implement compared to C-Band and Ku-Band.
First of all, there are many types of filter technologies that can be employed to make L-Band low pass filters. These include:
- L-Band Ceramic filter
- L-Band SAW filter
- L-Band LC filter
- L-Band Cavity Filter
- L-Band Suspended Stripline (SSL) Filter
AWG Tech specializes in providing L-band LC filters, L-Band Cavity Filter and L-Band Suspended Stripline Filter.
We also supply L-Band low pass filters to the telecom, commercial and defense sector. Contact us if you have any enquiry on our products.
ALPF-1920M-01: A 1.92 GHz SSL Low Pass Filter
ALPF-1920M-01 is an L-Band low pass filter with a cut-off frequency of 1.92GHz. It has a passband from dc to 1920MHz and has an insertion loss of less than 1 dB in the passband. It has a stopband rejection of better than 60 dB from 3.4GHz to 6GHz. Designed and manufactured using suspended stripline filter technology, ALPF-1920M-01 features low insertion loss, wide band operation and wide and steep stopband attenuation.
The table below summarizes some of standard L-Band low pass filters we have.
| Part Number | 1 dB Cutoff Frequency | Insertion Loss | Rejection | Description |
|---|---|---|---|---|
| ALPF-960M-01 | 960 MHz | 1.5 dB max | >70 dB @ 1.4~4 GHz | 960MHz Low Pass Filter, L-Band Suspended Stripeline Low Pass Filter |
| ALPF-1200M-01 | 1200 MHz | 2 dB max | >50 dB @ 2.2 GHz | 1.2 GHz Low pass filter, L-Band Low Pass Filter |
| APF-1450M-01 | 1450 MHz | 2 dB max | > 70 dB @ 3.1 GHz | 1.45 GHz Low pass filter, L-Band Low Pass Filter |
| ALPF-1920M-01 | 1920 MHz | 1 dB max | > 60 dB @ 3.4~6 GHz | 1.92 GHz Low pass filter, L-Band Suspended Stripline Low Pass Filter |
| ALPF-2000M-01 | 2000 MHz | 1.5 dB max | > 50 dB @ 2.5~13 GHz | 2 GHz Low pass filter, L-Band Suspended Stripline Low Pass Filter |
The Presence of L-Band Frequencies in GPS and Other Communication Devices
Every GPS data belongs to the L-Band frequency spectrum. This is due to the fact that L-Band waves are able to penetrate clouds, fog, rain storms and vegetation. In addition, these GPS units can receive fast information in every weather condition, at any time of the day. However, there are times where GPS units may not receive signals faster depending on where it’s placed, such as inside concrete buildings or under forest canopies.
First, what are L-Band Frequencies?
The L-Band, according to the IEEE, is defined as any frequency range that falls under 1 to 2 GHz range of the radio spectrum. The L-Band is also used in other devices and components, such as an L-Band low pass filter. This type of RF filter allows for the passage of low frequency signals and blocks high frequency signals from entering its circuit. With the L-Band frequency signals, low pass filters now function effectively despite any weather condition.
However, this particular frequency band is most commonly seen in Global Positioning Systems, or GPS.
Usage of L-Band Frequencies
First of all, the position identification principle by the GPS and the speed of the positions are highly dependent on the nature of the signals transmitted. The right signal foundation was manufactured to fulfill a number of requirements. The choice of the GPS carrier frequency (in transmitting data signals) was passed to the following needs:
- Frequencies are needed to be less than 2GHz, as frequencies above the said frequency would need a beam antenna for the reception of signals.
- Ionospheric delays are huge for frequency ranges lower than 1,000MHz and above 10GHz.
- The selected frequency should be in a certain range where signal reproduction is not influenced by the different weather phenomenon, such as rain, snow and cloudy skies.
Based on the above stated considerations, L-Band frequencies are proven to beneficial. Every GPS satellite transmits three carrier signals in the microwave range of the electromagnetic spectrum, designated as L1, L2 and L5 (these are frequencies situated in the L-Band between 1GHz to 2GHz).
The L1 frequency is 1,574.42 MHz (19.05 cm in wavelength), the L2 is at 1,277.60 MHz (24.45 cm in wavelength) and the L5 frequency is 1,176.45 MHz (25.48 cm in wavelength).
Importance of L-Band Frequencies in Communication
Communicating with the use of L-band frequency signals can help increase in productivity. Essential pieces of information can be sent and received in real time to help manage and improve production. For example, pressure, volume and flow gathered in regular intervals can stimulate remote adjustments to run assets effectively. Other times, real time information can unveil maintenance problems before outrage can take place or equipment failure.
Overall, L-Band frequency signals used in an L-Band Low Pass Filter, GPS devices and other communication devices tend to make communication process faster due to the said frequency to work even in extreme conditions. However, there are still limitations to the L-Band frequencies, like when the device is inside a concrete establishment or inside a forest.
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If you need more information regarding our L Band low pass filter, RF filters or any RF components, contact us by filling in the contact form below for a non-obligatory quotation. Our RF experts will be glad to assist you with your queries.