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“TPM-2606P2” All-in-one Radio Frequency (RF) Modules for LTE Small Cell Base Stations

The product is essential for stable communications of telecommunications equipment such as smartphones.

Product data

What is an all-in-one RF module for small cell base stations?

With the recent spread of smartphones and other mobile devices, mobile phone system traffic is increasing dramatically, and this leads to various problems such as reduced communication speed. As a promising means for coping with the above situation, operators have started to use “small cells” to exclusively cover small areas where traffic is concentrated with small base stations. We developed the all-in-one RF module TPM-2606P2 for such small base stations, based on the technology for the wireless transceivers (remote radio heads) for mobile phone stations.

Features of the all-in-one RF module TPM-2606P2

Our newly developed TPM-2606P2 incorporates all the RF circuits (transmitter amplifier, receiver amplifier and transmitter/receiver switch) necessary for constructing a 2.6 GHz-band TD-LTE*1 base station which will become widely used in the future. The circuits have the following features:

(1) A Doherty-type amplifier*2 is used in the transmitter amplifier, which is responsible for most of the energy consumption of an LTE base station, to enhance power utilization efficiency to 40% or more*3.

(2) A balanced amplifier is used in the receiver amplifier to achieve low-noise, high input power tolerance together with low reflectance properties of the antenna port.

(3) A combination with a circulator*4 lowers transceiver/receiver switching loss as well as power that passes through the switch, thereby enhancing the switching reliability.

(4) The new RF module includes a distortion compensation circuit that is essential to the highly efficient transmitter amplifier, thereby eliminating the need for additionally installing an expensive distortion compensation circuit outside the module. The included distortion compensation circuit prevents troubles at production sites such as non-compliance of the combined amplifier and distortion compensation circuit with the applicable standards.

RF circuits with these features are compactly modularized in the TPM-2606P2 to dramatically shorten base station development and production periods and promote the adoption of small cells.

*1
TD-LTE: A 4th-generation mobile phone communications system LTE that separates transmission and reception on a time-sharing basis
*2
Doherty-type amplifier: An amplification system consisting of two amplifiers arranged in parallel to operate one or both of them depending on the magnitude of the output power, thereby achieving both high output and high power utilization efficiency at the same time
*3
When outputting 6 W LTE signals
*4
Circulator: A passive electronic device consisting of three terminals
Interview with engineer in charge
Shuichi Nishimura
Radio Transmission Systems Department
Infocommunications and Social Infrastructure Systems R&D Center
Shuichi Nishimura

What were the difficulties in developing the module?

To reduce the size of the module designed for small base stations, we worked to reduce the sizes of components and develop high-density circuits. On the other hand, the reduced size leads to heat concentration in a small area, necessitating a metal board to be soldered onto the back of the print substrate to disperse heat. We need to be creative in solder mounting to tightly join the print substrate and metal board. After we repeatedly set conditions at the factory and promoted improved production jigs together with the production section, accurate mounting was enabled.

What features of our products are favored by customers?

Since most of the energy supplied when amplifying wireless signals by the amplifier is wasted as heat, it is important to enhance the power utilization efficiency of the amplifier and reduce power consumption. This module achieves high efficiency due to its incorporated distortion compensation circuit. By installing the module into a base station system, low energy consumption and good wireless properties can be achieved without complex controls. This easy introduction is favored by our customers.


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