1880 – 1930MHz L-Band Bandstop Filter

An L-Band bandstop filter is used to reject a small range of frequencies within the 1-2 GHz L-Band spectrum. AWG Tech supplies many types of L-Band notch filter to GSM equipment vendors. One of the most commonly used L-Band band reject filter is ABSF-1905MBW50-01.

ABSF-1905MBW50-01

ABSF-1905MBW50-01 is an L-Band cavity notch filter which provides more than 30dB rejection from 1880MHz to 1930MHz. It features a low insertion loss of not more than 1.5dB in the passband. It has two passbands. The lower passband is from dc to 1830 MHz and the upper passband is from 1.96GHz to 4.6GHz. ABSF-1905MBW50-01 is a compact in size and measures only 137mm X 42mm x 22mm.

More information about our band reject filters can be found here.

The Critical Tasks Performed By L-Band Band Stop Filters

When it comes to more complex satellite transmissions from commercial and government operators, the L-band is one of the most favored frequencies, because this part of the electromagnetic spectrum is the easiest to implement for satellite-stabilized systems (as it has lower frequencies). If you   compare the L-band with other bands like C, Ku or Ka, and equate it to real estate terms, the C-band could be the suburbs, the Ku-band would be the lush countryside, the Ka-band would be the prairies, and the L-band would be the mountain regions! Here are more stuff about the L-band, and how L-band band stop filters help manage or filter the transmission of signals.

The L-band is Low Frequency & Is Easier To Process

Of the different bands in the IEEE’s electromagnetic spectrum, the L-band is deemed as a relatively low frequency that’s very easy to process, requires less-complex and sophisticated (and less costly) radiofrequency equipment. And because it has a wider beam, the L-band antenna’s pointing accuracy doesn’t need to be as accurate as that of the much-higher bands. And with the use of high-quality L-band band stop filters, the signals are much clearer, with less intrusion and interference from outside signals.

The L-band covers the 1 to 2 gigahertz (GHz) range of the radiofrequency spectrum, and is used for satellite communications on Inmarsat, as well as for global positioning system (GPS) carriers, including the Galileo navigation system and GLONASS.

It’s also the band of choice for low-earth orbit satellites, military satellites and terrestrial wireless communications systems like GSM mobile phones. The L-band is even utilized as an “intermediate” frequency, especially when the Ku or Ka bands are down-converted to the L-band.

What Does A “Band-Stop” Filter Do?

Of the different types of RF filters, “band stop” filters are a unique bunch of equipments. According to electronics experts, this type of filter is constructed using a mix of low and high pass filters, and the name of the filter indicates that it stops a certain band of frequencies.

Band-stop filters are also called 2nd-order filters which have two cut-off frequencies. The main function or task of this filter is to pass all the frequencies from zero up to the first cut-off frequency point, along with the other frequencies above its second cut-off frequency.

What are the advantages of band-stop filters? According to communications experts, this type of filter is great, especially when transmitting or rejecting signals at high power levels. Perhaps the only drawback of the L-band is that there’s little room available in this frequency range, which also explains why it’s quite costly to get a desired frequency range or address.

Nevertheless, filters like this are widely used in electronics and communications circuits, as they kick out unwanted frequencies and allow other frequencies to pass, with only minimum loss.

And so for L-band band stop filters, the main tasks would be to pass above and below frequencies, and any frequencies that are between these two cut-off frequencies will be attenuated, or block/disabled.