5 results about "Fourth harmonic" patented technology

The invention provides a method for improving the discrimination threshold of laser methane telemetering equipment, which comprises the following steps: in a dark environment, turning off a laser of the laser methane telemetering equipment, and measuring a first harmonic light intensity value I1c, a second harmonic light intensity value I2c and a fourth harmonic light intensity value I4c; selecting a central wavelength of a laser, and selecting a standard methane gas chamber with a remote measurement value of Wt; calculating a proportionality coefficient k21 considering the influence of the white noise, and calculating a telemetry measurement value W21 after the compensation of the electrical noise; calculating a proportionality coefficient k41 considering optical noise influence and an estimated value W41 of a telemetering value, and calculating a credibility criterion F '; selecting a confidence interval [b-1, b]; the standard methane gas chamber is slowly deflated, Wreal is calculated in real time, when the methane concentration is reduced to enable all the calculated Wreal to be zero, the methane concentration value Cmin at the moment is measured, and the identification threshold Wmin of the laser methane telemetering equipment is obtained through calculation. According to the method for improving the discrimination threshold of the laser methane telemetering equipment, electrical noise can be compensated, and part of optical noise can be filtered out.

This invention discloses a dual-frequency deep ultraviolet laser generator, comprising a fundamental frequency seed source, a first harmonic conversion optical path, a second harmonic conversion optical path, and an output optical path. The first harmonic conversion optical path has a first beam combiner, a first second harmonic module, a third harmonic module, and a first delay line arranged sequentially along the propagation direction of the light. The second harmonic conversion optical path has a second beam combiner, a harmonic conversion optical path branch, and a second delay line. The harmonic conversion optical path branch and the second delay line are connected in parallel between the second beam combiner and the output optical path. The harmonic conversion optical path branch has a second second harmonic module and a fourth harmonic module arranged sequentially after the second beam combiner along the propagation direction of the light. The output optical path has a seventh harmonic module and an eighth harmonic module. This invention avoids the single-path power bottleneck by using distributed amplification, breaking through the power limitation of the fundamental frequency in traditional sum-frequency generation methods.

This invention belongs to the field of microelectronics technology and discloses a high-precision eight-phase voltage-controlled oscillator based on a transformer superharmonic coupling network. The oscillator includes four voltage-controlled oscillator units and a superharmonic coupling network, with each unit outputting a pair of differential oscillation signals. The superharmonic coupling network consists of two stage I coupling transformers and one stage II coupling transformer. The stage I coupling transformers are connected to the second harmonic output terminals of the first and second groups of voltage-controlled oscillator units, respectively, creating a 90° phase difference between the corresponding fundamental signals. The stage II coupling transformer is connected to the fourth harmonic coupling terminal of the stage I coupling transformer, creating a 90° phase difference between the second harmonic signals of the four units, thus ensuring that the eight fundamental output signals are sequentially 45° out of phase. This invention achieves high-precision eight-phase output by precisely controlling the fourth harmonic phase to regulate the second harmonic phase of each unit, while not interfering with the fundamental oscillation. It has advantages such as symmetrical structure, small phase error, and consistent output amplitude.

The application discloses a source degeneration type harmonic suppression frequency doubler, which comprises an input transformer, a transistor pair and a source degeneration network and an output transformer connected with the transistor pair in sequence, wherein the gate of the transistor pair is connected with the output end of the input transformer, the drain is connected with the output transformer, and the source is connected with the input end of the source degeneration network respectively. The application can realize high fundamental wave suppression ratio in the output frequency of more than 30GHz and a wide output frequency range by suppressing the output harmonic of the frequency doubler through the internally integrated source degeneration structure, and can simultaneously improve the fourth harmonic suppression ability through the harmonic impedance shaping technology while maintaining the wideband input matching characteristics.

The invention discloses a harmonic shaping oscillator circuit, which comprises a PMOS (P-channel Metal Oxide Semiconductor) cross coupling pair, an NMOS (N-channel Metal Oxide Semiconductor) cross coupling pair, a first source electrode inductance unit, a second source electrode inductance unit, a drain electrode inductance unit, a first adjustable capacitor pair, a second adjustable capacitor pair, a first differential fixed capacitor unit and a second differential fixed capacitor unit. The transformer formed by the first source electrode inductance unit, the second source electrode inductance unit and the drain electrode inductance unit can simultaneously realize differential mode third harmonic impedance expansion and double common mode resonance of second and fourth harmonics, and can avoid introduction of additional inductance while reducing flicker noise and phase noise, so that the stability of the filter is improved. No extra chip area is occupied, and the Q value of the resonant cavity is improved.