NAT-MCH-RTM-RF: MTCA.4 RF backplane control

COM Express carrier & rear transition module for MicroTCA.4 systems

Single slot solution providing an NAT-MCH-PHYS/NAT-MCH-PHYS80 with a fully user-accessible Intel® Core™ i7 CPU and storage and allowing full control of the optional RF backplane, located behind a standard MTCA.4 backplane.

The NAT-MCH-PHYS and NAT-MCH-PHYS80 and their associated rear transition module NAT-MCH-RTM-RF, all three members of the NAT-MCH family of products, bring additional flexibility and scalability to MTCA.4 systems.

This unique combination releases slots normally occupied by processor Advanced Mezzanine Cards (PrAMCs), storage and graphic AMCs by using the space behind the MCH slot(s) in a MicroTCA.4 chassis.

What's more, the NAT-MCH-RTM-RF allows the NAT-MCH-PHYS and the NAT-MCH-PHYS80 to fully control the RF backplane, which is located behind the standard MTCA.4 backplane for AMCs, and any item connected to this additional backplane, such as eRTM (extended RTM), RPM (Rear Power Modules) and (optionally) standard RTMs.

The RF backplane allows you to combine systems that are traditionaly separate - one for the digital part and one for the analogue part - into one singe MicroTCA system. The required mechanics and the management extensions have been introduced to the PICMG MTCA.4 working group already in order to make these optional extensions available as part of the open MicroTCA.4 standard.

Using rear power modules, any RTM that connects to the RF backplane can be powered independently from its associated AMC, thus providing a higher power budget per AMC/RTM slot combination.

Carrier for any Type-6 COM Express modules and Rear transition module for the NAT-MCH-PHYS and the NAT-MCH-PHYS80
The NAT-MCH-RTM-RF is a fully functional COM Express carrier in double-wide, full-size format, designed for any Type-6 COM Express module. The I/O as available from the COM Express module is brought to the front panel of the RTM. The NAT-MCH-RTM-RF connects to the NAT-MCH-PHYS and the NAT-MCH-PHYS80 via the zone 3 connector and offers the COM Express module an up to x16  PCIexpress Gen3 path to the PCIe switch on the NAT-MCH-PHYS/PHYS80 as well as a SATA connection. Both the NAT-MCH-PHYS and the NAT-MCH-PHYS80 are double-wide, full-size MCHs, with a special clock module providing low jitter and skew, and a PCIe switch module, providing Gen3 (30Gbps) bandwidth at the fat pipe and can be equipped with one or two SATA Flash Drives (SSD).

Single slot solution for management, switching and PCIe root complex
When equipped with the optional dual- or quad-core Intel® Core™ i7 Ivy Bridge COM Express module, the NAT-MCH-RTM-RF becomes the special version NAT-MCH-RTM-RF-COMex-i7 (dual-core) or NAT-MCH-RTM-RF-COMex-i7Q (quad-core, usage of rear power modules with RF backplane). Using the connections over the zone3 connector, the COM Express module has direct access to the facilities located on the NAT-MCH-PHYS or the NAT-MCH-PHYS80:
  • x4 link to the PCIe Gen3 fat pipe switch (Fabric D-G, NAT-MCH-PHYS)
  • x16 link to the PCIe Gen3 fat pipe switch (Fabric D-G, NAT-MCH-PHYS80)
  • 1GbE link to the 1GbE base fabric switch (Fabric A)
  • Two SATA connections to the two SSD mounting sites
Intel® Core™ i7 CPU and storage at user's discretion
Thus the NAT-MCH-RTM-COMex-i7 or NAT-MCH-RTM-COMex-i7Q function as fully-featured replacements for a PrAMC, which would occupy one AMC payload slot.

The NAT-MCH-RTM-COMex-i7 provides a fully user-accessible dual core Intel® Core™ i7 Ivy Bridge incl. ECC 4GB DDR3-1066.

While the NAT-MCH-RTM-RF-COMex-i7Q provides a fully user-accessible quad core Intel® Core™ i7 Ivy Bridge incl. ECC 8GB DDR3-1066.

Both versions offer high resolution graphics on two DisplayPorts, four USB3.0 and an additional 1GbE on the front panel of the NAT-MCH-RTM-RF-COMex-i7(Q). Further extension capabilities are offered by the optional MicroSD card slot.

Family of MCH products
The NAT-MCH-RTM is associated to the NAT-MCH family of MCHs which consists of:

Background: Low Level RF backplane (µRFB)

MicroTCA is a high-channel-density system standard. In order to increase system reliability and ease of maintenance, improve cable management, reduce performance limitations and the space occupied by external RF cabling, and finally for better EMC shielding of sensitive analog signals, the physics research community, including DESY and industry partners, were inspired to develop a unique concept for extending the MicroTCA.4 system capabilities.

The MicroTCA RF-Backplane (µRFB) for µRTM cards is a hardware implementation of this new extension embedded in a MicroTCA.4 crate. The unit is a passive RTM backplane suited for the interconnection of high-precision RF and CLK signals and the delivery of high-performance managed analog power supply for µRTM and extended RTM (eRTM) modules. High-frequency signal distribution network was designed to operate in the DC – 6GHz band.

More information about the MicroTCA RF-Backplane can be found in the document following this link.


Key features
Technical details
Block diagram
Order code
The NAT-MCH-RTM-RF is the standard rear transition module for both the NAT-MCH-PHYS and the NAT-MCH-PHYS80 and functions as carrier for any Type-6 COM Express module.
  • Connections to RF backplane
    • I2C interface to EEPROM
    • IPMI to two Rear Power Modules
    • IPMI to three eRTMs, which habe no connection to front AMCs
    • FPGA for a application specific intercommunication bus
  • MicroSD card slot
  • Mounting slot for any Type-6 COM Express module, I/O of COM Express slot connected to NAT-MCH-PHYS/PHYS80 via zone3 connector or available at front panel

Available with optional dual-core Intel® Core™ i7 (NAT-MCH-RTM-RF-COMex-i7) or quad-core Intel® Core™ i7 ( NAT-MCH-RTM-RF-COMex-i7Q)

  • I/O on front panel of RTM:
    • 2x DisplayPort (high resolution graphics)
    • 4x USB3.0
    • 1x GbE at rear panel
  • Connections to the NAT-MCH-PHYS and NAT-MCH-PHYS80
    • 2x SATA connection to two SSD slots
    • One x4 PCIe Gen3 link to fat pipe switch (Fabrics D-G, NAT-MCH-PHYS)
    • One x16 PCIe Gen3 link to fat pipe switch (Fabrics D-G, NAT-MCH-PHYS80)
    • One 1GbE connection to GbE switch (Fabric A)
(NAT-MCH-RTM-RF with mounted dual core Intel® Core™ i7 ComExpress module)
(NAT-MCH-RTM-RF with mounted quad core Intel® Core™ i7 ComExpress module, requires use of Rear Power Modules)

  • COM Express-Type 6 module


  • Dual-core Intel® Core™ i7 (1.7GHz)
  • Quad-core Intel® Core™ i7 (2.4GHz)


  • ECC 4GB DDR3-1066 (dual core)
  • ECC 8GB DDR3-1066 (quad core)

Rear Panel Connector

  • 2x DisplayPort (high resolution graphics)
  • 4x USB3.0
  • 1x 1GbE

Interconnect to Network

  • 2x SATA connection to two SSD slots on NAT-MCH-PHYS or NAT-MCH-PHYS80
  • One x4 PCIe Gen3 link to fat pipe switch (Fabrics D-G) on NAT-MCH-PHYS
  • One x16 PCIe Gen3 link to fat pipe switch (Fabrics D-G) on NAT-MCH-PHYS80
  • One 1GbE connection to GbE switch (Fabric A) on NAT-MCH-PHYS/NAT-MCH-PHYS80

  • MicroSD card slot


  • One 2.5 inch SSD with 128 GB mounted on NAT-MCH-PHYS or two 1.25 inch SSD in RAID mode on request mounted on NAT-MCH-PHYS

Operating System

  • Linux, Windows, WindRiver O/S (VxWorks, Linux, Hypervisor)


  • MTCA.0 R2.0, MTCA.4 R1.0, AMC.0 R2.0, AMC.1, AMC.2, AMC.4, IMPI V1.5 & V2.0, EN60950, UL1950, RoHS

Rev #
Date Last Modified
nat-mch_ds Data sheet and NAT-MCH family overview pdf 1.179 KB 1.4 06-07-2012
MicroTCA RF-Backplane data sheet MicroTCA RF-Backplane data sheet   pdf 639 KB   2.0 19-12-2014 
nat_mch_rtm_comex_v2x_man_hw   Hardware Manual for RTMs v2.x pdf  1.3 MB  1.0 04-04-2016

For further documentation on the NAT-MCH (i.e. technical reference manuals) please contact us using the contact form. Thank you.

NAT-MCH-RTM block diagram

Product Code: NAT-MCH - [Options]

-RTM Double-wide full-size rear transition module and COM Express carrier Type-6 COM Express modules
-RTM-COMex-i7 Like option -RTM but with dual-core Intel® Core™ i7 (1.7GHz) COM Express module 4GB DDR3-RAM
-RTM-COMex-i7Q Like option -RTM but with dual-core Intel® Core™ i7 (2.4GHz) COM Express module 8GB DDR3-RAM
requires Rear Power Module



NATView Java based GUI (Graphical User Interface) for monitoring and control of MTCA systems. 2.25 26-08-2016
NBSP-LINUX-NAT-MCH-RTM Ubuntu Linux for NAT-MCH-RTM-COMex-i7 and NAT-MCH-RTM-COMex-i7Q 12.0.4 04-2012