Sheet type LTCC miniaturized 3dB directional coupler

Abstract

The invention discloses a sheet type LTCC miniaturized 3dB directional coupler which is wide in frequency band, small in size, stable in temperature performance, small in insertion loss, balanced in amplitude and good in phase balance characteristics. The sheet type LTCC miniaturized 3dB directional coupler comprises four ports which are printed at the four corners on the bottom surface of a first bottom substrate and are provided with impedance input of 50 ohms, i.e., an input port, a straight-through port, a coupling port and an isolation port. The input port and the straight-through port are connected with a first coupling band-shaped wire on a second substrate through a first asymmetric band-shaped wire and a third asymmetric band-shaped wire which are arranged on the same substrate. The coupling port and the isolation port are connected with a second coupling band-shaped wire on a third substrate through a second asymmetric band-shaped wire and a fourth asymmetric band-shaped wire which are arranged on the other same substrate. The first coupling band-shaped wire and the second band-shaped wire represent rotary-shaped patterns and are coupled in a band-shaped mode at upper wide edges and lower wide edges. According to the invention, the coupling wires represent the rotary-shaped patterns so that quite large coupling wire length can be obtained on a limited substrate area, thus a quite wide frequency scope is obtained. The sheet type LTCC miniaturized 3dB directional coupler has the advantages of simple structure, high yield, good batch consistency and low cost.

Description

technical field [0001] The invention relates to a microwave component used for wireless communication or radar sending and receiving signals, in particular to a chip type LTCC (also known as low temperature co-fired ceramic technology) miniature 3dB directional coupler. Background technique [0002] Microwave directional couplers are used in radio frequency and microwave transmission systems to distribute, synthesize, power sample and detect the power of transmission signals, and are important components of balanced amplifiers, analog and digital phase shifters, analog and digital attenuators, etc. part. The standard microwave directional coupler is a four-port network that divides the input signal power into two output signals with a certain ratio within the set frequency range. When the directional coupler is used to transmit the signal in reverse, it will have the effect of power synthesis. [0003] Chip LTCC miniature 3dB directional coupler is an important electronic c...

AI Technical Summary

Problems solved by technology

[0019] The directional coupler in the prior art has disadvantages such as narrow bandwidth, large volume, high cost and not suitable for mass production due to the traditional air bridge design method, photolithography first and then electroplating process and thick film multi-layer substrate technology.

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