User guide

Indoor RF unit (IRFU) Chapter 1: Product description
1-18
phn-2513_004v000 (Oct 2012)
Indoor RF unit (IRFU)
This section describes the PTP 800 IRFU and its interfaces.
IRFU description
The PTP 800 indoor RF unit (IRFU) (Figure 10) converts signals between a modulated
intermediate frequency (IF) and radio band frequencies for transmission over a line-of-
sight link. The IRFU can be chosen as an alternative to the ODU to operate with one or two
PTP 800 CMUs.
Figure 10 Top and front view of IRFU shelf (with single transceiver and waveguide)
The PTP 800 IRFU platform supports the licensed bands and frequencies listed in Table 3.
The IRFU chassis is designed for mounting in an indoor 19" rack. The 2.77 U height
chassis can house one or two field replaceable transceivers, where each transceiver
interfaces to a separate CMU via an intermediate frequency coaxial cable, or IF cable. The
IRFU also provides either one or two waveguide interfaces for connection to the antenna
or antennas. The waveguide interfaces have excellent voltage standing wave ratio (VSWR).
This reduces the amplitude of reflected signals passing up the waveguide which could
otherwise degrade the quality of the transmitted and received signals. When connected to
a suitably low VSWR antenna, this makes the IRFU ideal for operation with a wide range of
waveguide lengths.