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Sichuan Keenlion Microwave Technology——Combiner


Sichuan Keenlion Microwave Technology——Combiner

Sichuan Keenlion Microwave Technology Founded in 2004, Sichuan Keenlion Mircrowave techenology CO., Ltd. is the leading manufacturer of the Passive Mircrowave components in Sichuan Chengdu, China.

We provide high-performance mirrowave components and related services for microwave applications at home and abroad. The products are cost-effective, including various power divider, directional couplers, filters, combiners, duplexers, customized passive components, isolators and circulators. Our products are specially designed for various extreme environments and temperatures. Specifications can be formulated according to customer requirements and are applicable to all standard and popular frequency bands with various bandwidths from DC to 50GHz.

Combiner

In the wireless mobile communication system, the main function of combiner is to combine the input multi band signals and output them to the same indoor distribution system

In engineering application, 800MHz C network, 900MHz G network or other different frequencies need to be output at the same time. Using combiner, a set of indoor distribution system can work in CDMA frequency band, GSM frequency band or other frequency bands at the same time.

For example, in the radio antenna system, the input and output signals of several different frequency bands (such as 145mhz and 435mhz) are combined through the combiner, and then connected with the radio station with a feeder, which not only saves a feeder, but also avoids the trouble of switching different antennas.

 

 

Effect

In engineering applications, it is necessary to combine 800MHz C network and 900MHz G network. Using combiner, a set of indoor distribution system can work in CDMA band and GSM band at the same time. For another example, in the radio antenna system, the input and output signals of several different frequency bands (such as 145mhz and 435mhz) are combined through the combiner, and then connected with the radio station with a feeder, which not only saves a feeder, but also avoids the trouble of switching different antennas.

 

Principle analogy description

The combiner is generally used at the transmitting end. Its function is to combine two or more RF signals sent from different transmitters into one and send them to the RF devices transmitted by the antenna, while avoiding the interaction between the signals of each port.

Combiners generally have two or more input ports and only one output port. Port isolation is an important index to describe the ability of two signals not to affect each other. It is generally required to be more than 20dB.

3dB bridge combiner has two input ports and two output ports, as shown in Figure 2. It is commonly used to synthesize two wireless carrier frequencies and feed them into antenna or distribution system. If only one output port is used, the other output port needs to be connected to a 50W load. At this time, there is 3dB loss after the signal is combined. Sometimes both output ports need to be used, so there is no load and no 3dB loss.

Combine the receiving and sending of the signal mobile phone to one antenna. In the GSM system, because the transceiver is not in the same time slot, the mobile phone can omit the duplexer for isolating the transceiver, and only use a simple transceiver combiner to combine the sending and receiving signals into one antenna without interfering with each other.

For the receiving circuit, the antenna receives the signal, enters the receiving channel through the combiner, mixes with the received local oscillator signal (i.e. the received VCO signal generated by the frequency synthesizer), changes the high-frequency signal into an intermediate frequency signal, and then quadrature demodulates the signal to generate the received I and Q signals; Then GMSK (Gaussian filter minimum frequency shift keying) demodulation is carried out to convert the analog signal into digital signal, and then sent to the baseband processing unit.

For the transmission circuit, the baseband part sends the TDMA frame data stream (with a rate of 270.833kbit / s) for GSMK modulation to form the transmission I and Q signals, which are then sent to the transmission up converter for modulation to the transmission frequency band. After power amplification, the transmitter sends it out by the antenna.

The frequency synthesizer provides the local oscillator signal necessary for frequency conversion for the transmitting and receiving unit, and uses the phase-locked loop technology to stabilize the frequency. It obtains the frequency reference from the clock reference circuit.

The clock reference circuit is generally 13mhz clock. On the one hand, it provides clock reference for frequency synthesis circuit and working clock for logic circuit.

Main classification

Dual frequency combiner

① JCDUP-8019

GSM & 3G dual frequency combiner is a two in and one out device. GSM signal (885-960mhz) can be combined with 3G signal (1920-2170MHz).

② JCDUP-8028

DCS & 3G dual frequency combiner is a two in and one out device. DCS signal (1710-1880mhz) can be combined with 3G signal (1920-2170MHz).

③ JCDUP-8026B

(TETRA / iden / CDMA / GSM) & (DCS / PHS / 3G / WLAN) dual frequency combiner is a two in and one out device. One port covers tetra / iden, CDMA and GSM system frequency band (800-960MHz), and can input tetra / iden, CDMA, GSM or any combination thereof; The other port covers the frequency band of DCS, PHS, 3G and WLAN system (1710-2500mhz), and can input DCS, PHS, 3G, WLAN or any combination of them.

④ JCDUP-8022

(CDMA / GSM / DCS / 3G) & WLAN dual frequency combiner is a two in and one out device. One port covers CDMA, GSM, DCS and 3G system frequency band (824-960 / 1710-2170mhz), and can input CDMA, GSM, DCS, 3G or any combination thereof; The other port covers the WLAN system frequency band (2400-2500mhz) and can input WLAN system signals.

Three frequency combiner

① JCDUP-8024 / JCDUP-8024B

GSM & DCS & 3G three frequency combiner is a three in and one out device. GSM (885-960mhz), DCS (1710-1880mhz) and 3G (1920-2170MHz) signals can be combined.

② JCDUP-8018

GSM & 3G & WLAN three frequency combiner is a three in and one out device. GSM (885-960mhz), 3G (1920-2170MHz) and WLAN (2400-2500mhz) signals can be combined.

Four frequency combiner

① JCDUP-8031

GSM & DCS & 3G & WLAN four frequency combiner is a four in one out device. GSM (885-960mhz), DCS (1710-1880mhz), 3G (1920-2170MHz) and WLAN (2400-2483.5mhz) four frequency signals can be combined.

In addition, in the application of combiner, it should be noted that the signal feeding mode of base station or repeater is wireless, and its source is wide spectrum. Therefore, narrow passband is required in some cases to ensure the purity of the signal; The signal feeding mode of combiner is cable, and the signal is directly taken from the source, which is a narrow spectrum signal. For example, the CDMA / GSM channel of combiner jcdup-8026b has a channel width of 800-960MHz. When accessing a GSM carrier frequency signal, because the source is a carrier frequency signal, the feeding method is cable, and there is only this carrier frequency signal in the channel without other interference signals. Therefore, the wide channel design of combiner is feasible in practical application.


Post time: Feb-21-2022