Combined X/L-Band Option

If reception of L-Band NOAA HRPT and Metop AHRPT data is required using the same antenna system, additional RF components can be supplied to allow that.

If L-Band GOES HRIT or GEO-KOMPSAT-2A (GK-2A) LRIT/HRIT reception between polar-orbiter passes is also required, again using the same antenna system, a USB interface and additional software can be supplied.

The X/L-Band feed has 4 dipoles spaced 90° apart around the outside of the X-band scalar feed, and a quad hybrid combiner. The L-Band signal is fed to a pre-LNA 3-pole cavity filter followed by a single stage LNA, 4-pole combline bandpass filter and block downconverter.

An additional RF cable feeds the L-Band signal from the antenna system to the second RF input on the system interface rack. The RF module downconverts the signal to a common frequency of 140MHz and feeds that to the demodulator which converts it back to a binary data stream. HRPT and AHRPT data is byte-aligned and streamed via a TCP socket to the Polar Orbiter Ingester software running on the ingest PC.

A USB interface and Geostationary Ingester software can be supplied for GOES HRIT or GK-2A LRIT/HRIT reception between polar-orbiter passes. This is fed by the demodulator clock and data outputs and forms a byte-aligned binary data stream which is fed via USB to the Geostationary Ingester software running on the ingest PC.

L-Band Pre-LNA filter specifications
Type 3-pole cavity filter
Passband 1680–1710MHz
Passband loss 0.15dB
Bandwidth –3dB ±86MHz centred on 1705MHz
Stopband loss 300MHz: –80dB
1200MHz: –35dB
1570MHz: –10dB
1866MHz: –10dB
3000MHz: –50dB
L-Band LNA specifications
Type Single stage advanced E-PHEMT technology
Noise figure 0.5dB typical
Gain 20dB minimum
IP3 32dBm typical
Temperature –40 to +85°C operational
L-Band post-LNA bandpass filter specifications
Type 4-pole, Combline
Insertion loss 1.5dB max
Bandwidth 1690–1710MHz
L-band feed specifications
Type 4 dipoles with quad hybrid combiner
Polarisation RHC
L-Band block downconverter specifications
Noise figure 0.75dB typical
Input frequency 1682–1710MHz
LO frequency 1553.500MHz
Output frequency 126.5–154.5MHz
Converted bandwidth 50MHz @ 3dB typical
Conversion gain >50dB, 55dB typical
Image rejection >60dB
Input/output impedance 50Ω
Output 1dB comp. point >+14dBm
LO stability ±2.5ppm (–30 to +60°C)
LO type Internal PLL locked to TCXO
Phase noise –103dBc/Hz @ 10Hz typical
–130dBc @ 100kHz
Input voltage 10–15V DC @ 350mA typical powered via IF output cable
Temperature –40 to +60°C operational
Humidity 100% operational

Sample Images