Ultra-wideband frequency band synthesis circuit

Abstract

The invention discloses an ultra-wideband frequency band synthesis circuit. The ultra-wideband frequency band synthesis circuit comprises a through path and a coupled path. A low frequency band input port and a synthesis output port are arranged on two ends of the through path. A high frequency band input port and a load port are arranged on two ends of the coupled path. The through path and the coupled path are composed of microstrip lines. The microstrip lines are made of ceramic sheets or white sapphire sheets. Both the thickness and the width of the microstrip lines are 0.127 mm, and coupled gaps among the microstrip lines are 0.127mm. The ultra-wideband frequency band synthesis circuit has the advantages that 250KHz-70GHz frequency band synthesis bandwidth requirements are met, the borne power is relatively large, the loss of the frequency high end is less than that of a conventional method, and the power of the high end is saved.

Description

technical field [0001] The invention relates to an ultra-wideband frequency band synthesis circuit. Background technique [0002] With the continuous development of testing technology, the requirements for microwave testing instruments are higher and higher operating frequencies and wider operating frequency bands. At present, the high-end requirements for microwave testing instruments with coaxial output have reached 70GHz, and the low-end frequency bands have reached 70GHz. It is also required to reach 250kHz, the output power is required to be above +20dBm (the low-frequency input power can reach +30dBm), and the harmonics of the signal path are required to be above 60dBc. It is difficult to directly generate and process such wide-band RF signals, which must be segmented first. The method of post-synthesis is realized, which provides high requirements for the working bandwidth, withstand power and transmission loss of the frequency band synthesis circuit. The existing te...

AI Technical Summary

Problems solved by technology

[0006] The first technology is to use MMIC switches implemented by field effect transistors to realize frequency band synthesis. Its frequency range basically meets the frequency band synthesis requirements of 250kHz-70GHz, but its disadvantages are that the compression point is relatively low and the high-end frequency loss is relatively large.

The P-1dB of the 100MHz-70GHz frequency band is +15dBm (the compression point is lower below 100MHz). When the input power is close to +15dBm, the harmonic characteristics will deteriorate sharply, so it can only be used in the occasion of low-power broadband frequency band synthesis; And its transmission loss gradually increases with the increase of operating frequency, it is 2.6dB at 50GHz, about 4dB at 70GHz, and the high-end loss is relatively large

[0007] The second technology is to use PIN diode MMIC switch to achieve frequency band synthesis. At present, the best broadband switch operating frequency is 50MHz-50GHz, and the highest frequency can barely be extended to 70GHz, but its insertion loss index cannot be guaranteed. 50MHz, the frequency band below 50MHz cannot work, this technology can only barely meet the frequency band synthesis occasions of 50MHz-70GHz, and the bandwidth cannot fully cover the bandwidth of 250KHz-70GHz

In terms of power, this technology does not give a P-1dB index for the 50MHz-50GHz frequency band, but only gives a burning power of +23dm. According to the technical principle, it is inferred that P-1dB is much lower than +23dm. Using this technology to exceed +23dBm will cause the switch to burn out , with limited power; in terms of transmission loss, performance indicators are only given below the 50GHz frequency band, and no specific indicators are given for the 50GHz-70GHz frequency band

Therefore, the use of this technology can neither meet the bandwidth requirements nor meet the frequency band synthesis occasions with large input power. Its main disadvantages are that the frequency band is not wide enough, the withstand power is not high enough, and the high frequency loss is large.

[0008] To sum up, the existing two technologies cannot fully meet the bandwidth and input power requirements of the synthesis circuit in the 250kHz-70GHz frequency band, and its transmission loss increases with the increase of frequency, and the high-end loss is large

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