Grading bypass circuit for tower amplifier and control method thereof

Abstract

The invention discloses a grading bypass circuit for a tower amplifier and a control method thereof; the circuit comprises a preamplifier, a post amplifier, three selector switches and two branch circuit connecting lines with lambda / 2 length, each selector switch is provided with a common terminal and one of movable ends, which is connected with the common terminal, all the selector switches are controlled to carry out comprehensive switching by combining the working state of the preamplifier and the post amplifier, so as to lead the circuit to have a state I that a first selector switch, thepreamplifier, a second selector switch, the post amplifier and a third selector switch which are conducted sequentially; and a state II that the first selector switch, the preamplifier, a second branch circuit connecting line and a third selector switch which are conducted sequentially; and a state III that the first selector switch, a first branch circuit connecting line and the third selector switch which are conducted sequentially; the invention simplifies the structure of the grading bypass circuit, and the cost is reduced correspondingly; on the electrical performance, bypass loss and thewhole power consumption are further reduced.

Description

technical field [0001] The invention relates to a graded bypass circuit for a tower top amplifier and a control method thereof. Background technique [0002] The Tower Mounted Amplifier (TMA) is a new type of network optimization that reduces the receiving noise figure of the entire system, improves the receiving sensitivity of the entire system, and improves the receiving performance of the base station by adding a low-noise amplifier at the front end of the base station receiving system, that is, close to the receiving antenna. equipment. [0003] All tower mounted amplifiers have a bypass function, especially high gain tower amplifiers also have a graded bypass function. The common hierarchical bypass methods are as follows: figure 1 shown. The amplifier includes a pre-amplifier A1 and a post-amplifier A2. Two SPDT switches S1, S2, S3, and S4 are connected to both sides of the amplifiers A1 and A2 respectively, and the single-pole double-throw switches on both sides of...

AI Technical Summary

Problems solved by technology

But it is worth noting that A2 is a booster power amplifier. In order to ensure high enough gain and linearity, the noise figure is at least 2dB higher than that of A1 (low noise amplifier). A2 working alone is equivalent to the noise figure of a tower amplifier. As the tower rises, the main role of the tower in the network will also disappear, so this situation should not exist

[0006] From the above analysis, it can be seen that in the existing hierarchical bypass circuit, in the important fault mode, 4 switches are connected in series on the link, resulting in excessive bypass loss, and the number of switches is too large, resulting in high power consumption and high cost of the whole machine no less

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