CN2402081Y - Device for improving high frequency signal attenuation in cable television distributor - Google Patents

Abstract

The utility model relates to a device for improving high frequency signal attenuation in a cable television distributor. An iron core is used for penetrating any position of an impedance coil lead wire, which can isolate high frequency (RF) signals and electrical signals from separating and compensating the impedance matching of appointed frequency bandwidth; while a high-frequency transformer (coupler) can not be influenced to enable the high frequency signals to produce attenuation or distortion.

Description

Improve the device of catv distributor high-frequency signal decay

The utility model is the device that improves the decay of catv distributor high-frequency signal for a kind of, is applied on the distributor of distributing signal in the cable television network system, and is to make the not device of induced attenuation of high-frequency signal.

(the Community Antenna Television Service of cable television network system, CATV) be to utilize coaxial cable to receive or the network system of transmitting television signals, because the cable television network system is the mode (system merchant is to the user) of one-to-many, and be long-distance transmissions, except that utilizing coaxial cable, still need and use amplifier (Amplifier), distributor (Multi Tap), power inserter equipment such as (Power Inserter), make transmission signals be connected to user side; Yet, each equipment that is connected with coaxial cable all might cause the decay of transmission signals or add noise, and influences the rating quality of user side, so the employed equipment of cable television network system all must overcome this problem.

The current cable network system connects user side by coaxial cable, coaxial cable removes transmitting radio frequency signal (Radio Frequency, RF) outside, and suitably adding power inserter (Power Inserter) to be written into power supply, to supply each equipment required power supply apart from meeting; With regard to regard to distributor, distributor is that transmission signals is distributed into multichannel, shown in " Fig. 1 ", the circuit block diagram of at present visible distributor, wherein main signal has comprised radiofrequency signal (RF) and has been loaded with power supply signal (AC90V10A), distributor mainly is by distributor circuit 41 (Splitter), coupling circuit 42 (Coupler, high frequency transformer) and main signal input port 43, main signal output port 44 constitutes, distributor circuit 41 has first output port 411 and second output port 412, main signal is divided into two, in coupling circuit 42 2 ends electric capacity 45 is set, 46, main signal enters obstruct via electric capacity 45 by main signal input port 43, filtering low frequency signal filtering with main signal, high-frequency signal and power supply signal are distributed, high-frequency signal transfers to distributor circuit 42 via coupling circuit 42, and by first output port 411 and 412 outputs of second output port, also being written into power supply signal again converges into main signal and high-frequency signal can transmit back coupling circuit 42 again, and, transfer to next place by 44 outputs of main signal output port; Wherein be provided with inductance coil 47 (impedance coil) and came the rate power supply signal in 45,46 of two electric capacity.

As shown in Figure 2; for effectively intercepting radiofrequency signal; usually can in inductance line chart 47, add unshakable in one's determination 48; unshakable in one's determination 48 can make inductance increase magnetic field; inductance value increases; the effect of isolating high-frequency signal is good; yet the magnetic field force of inductance; big then contiguous coupling circuit is exerted an influence; promptly in fact only need filtering to specify the signal (low frequency signal) of frequency range; and high-frequency signal is separated with power supply signal, intercept radiofrequency signal (high frequency and low frequency signal) fully but iron core is set in the inductance coil, thereby whole signal attenuation value is increased.

Main purpose of the present utility model is to provide the device that improves the decay of catv distributor high-frequency signal, and particularly the impedance matching of frequency range is specified in compensation, and can not influence high frequency transformer (coupler), makes unlikely generation decay of high-frequency signal or distortion.

According to the disclosed device that improves the decay of catv distributor high-frequency signal of the utility model, distributor wherein includes distributor circuit, coupling circuit and main signal input, output port, this distributor circuit is provided with first output port and second output port, these coupling circuit two ends are provided with electric capacity, it is characterized in that: between this two electric capacity, be provided with an inductance coil, be equipped with a toroidal core in the heart in the lead-in wire body shaft of this inductance coil.

Wherein this toroidal core can be arranged on arbitrary position on the inductance coil.

For making the purpose of this utility model, shape facility and function thereof there are further understanding, cooperate diagram to be described in detail as follows now, wherein:

Fig. 1 is known allotter circuit block schematic diagram.

Fig. 2 is known dispensing arrangement schematic diagram.

Fig. 3 A is circuit box schematic diagram of the present utility model.

Fig. 3 B is the equivalent circuit diagram in the utility model.

Fig. 4 is dispensing arrangement schematic diagram of the present utility model.

Shown in " Fig. 3 A; Fig. 3 B ", according to the disclosed device that improves the decay of catv distributor high-frequency signal of the utility model, distributor wherein mainly is by distributor circuit 10 (Splitter), coupling circuit 11 (Coupler, high frequency transformer) and main signal input port 12, main signal output port 13 constitutes, distributor circuit 10 has first output port 101 and second output port 102, main signal is divided into two, in coupling circuit 11 2 ends electric capacity 14 is set, 15, main signal enters obstruct via electric capacity 14 by main signal input port 12, low frequency signal filtering with main signal, high-frequency signal and power supply signal are distributed, high-frequency signal transfers to distributor circuit 10 via coupling circuit 11, and by first output port 101 and 102 outputs of second output port, also being written into power supply signal again converges into main signal and high-frequency signal can send back coupling circuit 11 again, and, transfer to next place by 13 outputs of main signal output port; Wherein be provided with on the lead-in wire of inductance coil 16 with a toroidal core 17 on lead-in wire in 14,15 of two electric capacity, the equivalent electric circuit of toroidal core 17 on inductance coil 16 lead-in wires is shown in Fig. 3 B, and its characteristic impedance computing formula is as follows: $Z=\sqrt{\frac{R+\mathrm{JWL}}{G+\mathrm{JWC}}}$

In the formula, R+JWL represents series impedance, G+JWC represents to be close to the road admittance, and this inductance coil contains another inductance (toroidal core) can compensate the impedance matching of specifying frequency range, and can not exert an influence to contiguous coupling circuit 10 (high frequency transformer) and cause signal attenuation.

Utilize a toroidal core to run through arbitrary position of impedance coil lead-in wire according to the disclosed device that improves the decay of cable TV distributor circuit high-frequency signal of the utility model, can isolate high frequency (RF) signal separates with the signal of telecommunication, and the impedance matching of frequency range is specified in compensation, and can not influence high frequency transformer (coupler), make unlikely generation decay of high-frequency signal or distortion.

Only the above person only is the utility model preferred embodiment wherein, is not to be used for limiting the scope that the utility model is implemented; Be that all equalizations of being done with the utility model claim change and modification, be all claim of the present utility model and contain.

Claims (2)

1. one kind is improved the device that the catv distributor high-frequency signal is decayed, distributor wherein includes distributor circuit, coupling circuit and main signal input, output port, this distributor circuit is provided with first output port and second output port, these coupling circuit two ends are provided with electric capacity, it is characterized in that: between this two electric capacity, be provided with an inductance coil, be equipped with a toroidal core in the heart in the lead-in wire body shaft of this inductance coil.

2. the device that improves the decay of catv distributor high-frequency signal according to claim 1 is characterized in that wherein this toroidal core can be arranged on arbitrary position on the inductance coil.

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