Coaxial Multi-Line Connectors for 3G Mobile Phone Standards

Author: Markus Witte & John Lei

The demand for solutions providing a broader data bandwidth for mobile multimedia applications will be met by the 3G Mobile Telephone System Standards. A data transmission speed of up to 2 MB per second will enable users to download video or audio files on their way to the office or when on the move.

The global 3G market is currently being served by more than 130 providers. By October 2004, the number of subscribers to the 3G network will have increased to more than 40 million and the trend is expected to continue to rise. The Chinese market in particular would appear to be the driving force in 3G technology; moreover, the government will be granting the respective licenses by the middle of 2005. The 3G statistics for China show an expected 10,000 inhabitants per node B (node B = Base station). The installation of the network will take approximately three years. The network is expected to be used by 120 million subscribers by the year 2008. This special year will revolve around the Olympic Games in Beijing. The aim is to crown this top flight sports highlight with a perfectly functioning network.


The situation and conditions outlined above will most certainly spark fierce competition among the providers of technology standards (such as WCDMA (Wideband Code Division Multiple Access), TD-SCDMA (Time Division Synchronous Code Division Multiple Access) and CDMA2000 (Code Division Multiple Access)), and, of course, among the providers of Node B technology (base station) as well as the manufacturers of mobile phone technology for end users. On the other hand, given the growing Chinese population and their tremendous enthusiasm for technology, mobile handsets should be readily available on the mass markets. In connection with competitive pricing policies, this will firmly establish 3G as the globally leading technology.

Block diagram of a typical B node

Global Project Team

Solution with backplane frame

During the development of a new base station to 3G standards (Node B) in China, HARTING staff from Germany discussed the aspect of connector solutions for the Node B infrastructure with their colleagues from the Chinese project team. In their meetings, this global project team developed a number of client solutions.

The typical frequency range between the transceiver and power amplifier or low-noise amplifier contains a frequency spectrum of up to 2.5 GHz. The radio device communicates with the digital processing unit in the MHz range. The connectors used for the transmission of the digital signals are products from the har-bus® HM, har-pak® or DIN families.

Functions of the main blocks:

  • RF front-end: Filtering, combining, distributing, isolating
  • Transceiver: Conversion of the RF / base band
  • Digital data processing: Compression, multiplexing, coding, decoding, monitoring, warning messages, clocking, channeling
  • Network interface: Connection to the Radio Network Controller RNC

Application Solution

Mini Coax: cable assembly

As a result of international cooperation, the HARTING team was able to provide clients with Mini Coax products without product modifications and within a very short period of time. A number of client applications required signal routing through the PCB backplane as shown in Fig. 2. In order to reduce signal interference to an absolute minimum, HARTING has developed a new backplane feed-through for the existing product. In this layout, the frame supports „board-to-cable“ or „cable-to-cable“ connection through the backplane.

The solution with board-to-backplane frame offers maximum performance for signal transmission. Cut-outs in the backplane are in frequent use and therefore they do not represent a significant cost factor in most instances.


Right angled module

The large number of local providers of base stations for the 3G infrastructure is opening up the Chinese market for HARTING Mini Coax connectors. In view of the government support of Chinese products for base stations the HARTING solution should enjoy strong sales opportunities. We are ready for 3G in China and in the run-up to the 2008 Olympic Games.

Markus Witte

Senior Design Engineer


Signal Integrity & CAE
HARTING Electronics GmbH & Co. KG
Markus Witte

John Lei

Product Manager Mini Coax


HARTING Electronics GmbH & Co. KG
John Lei