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 |