4results about How to "Reduce dispersion effect" patented technology

The present invention discloses a novel impedance transformation network broadband Doherty power amplifier and a design method thereof, wherein a power divider is used to divide the radio frequency input power equally, one end output is connected to a carrier power amplifier circuit, and the other end is connected to a peak power amplifier circuit; the carrier power amplifier circuit includes a carrier power amplifier input and output bias / matching circuit and a carrier power amplifier; the peak power amplifier circuit includes a phase compensation line, a peak power amplifier input and output bias / matching circuit and a peak power amplifier; the input end of the impedance transformation network is connected to the output ends of the carrier power amplifier circuit and the peak power amplifier circuit, and the output end of the impedance transformation network is connected to a load. The present invention utilizes the principle of active load traction to ensure that the load in the Doherty power amplifier is always kept at an optimal impedance value for the carrier power amplifier, and the dispersion effect of the frequency is weakened to expand the bandwidth.

This invention discloses a graded-index non-zero dispersion-shifted optical fiber based on orbital angular momentum modes, comprising an optical fiber body including a ring core and an optical fiber cladding surrounding the ring core. The optical fiber cladding includes a circular region inside the ring core and an outer optical fiber cladding outside the ring core. This invention aims to provide a feasible optical fiber structure for suppressing four-wave mixing to meet the requirements of low-dispersion transmission of multiple orbital angular momentum modes.

The invention discloses a microwave atomic force microscope probe based on a coplanar waveguide structure and a preparation method, and belongs to the field of micro-nano detection and atomic force microscopes. The probe comprises a clamping part and a cantilever beam, a central conductor is laid on the axes of the upper surfaces of the clamping part and the cantilever beam, grounding metal layers are symmetrically arranged on the two sides of the central conductor at certain intervals, the grounding metal layers and the central conductor are parallel and equal in length, and the central conductor, the grounding metal layers and gaps between the central conductor and the grounding metal layers form a clamping part coplanar waveguide structure; and the central conductor and the grounding metal layer of the clamping part are respectively connected with the central conductor and the grounding metal layer of the cantilever beam to form a microwave transmission circuit, and the microwave transmission circuit is converted into a coaxial transmission line structure at the needle point to transmit a microwave signal to the needle point, so that emission and receiving of a near-field microwave signal are realized. According to the invention, the design is flexible, integration is easy, low-loss and low-dispersion transmission of microwave signals is facilitated, the design complexity and manufacturing cost of the probe are reduced, and effective support is provided for micro-nano detection and an atomic force microscope technology.

The present invention relates to a CPW-fed high-isolation dual-stopband MIMO antenna, comprising a substrate, an antenna and a ground plane, characterized in that the antenna comprises two radiating units, each radiating unit contains a circular monopole UWB antenna, the two circular monopole UWB antennas are perpendicular to each other, and the circular monopole UWB antenna corrodes an SRR slot. Compared with the prior art, the coplanar waveguide feeding method of the present invention can reduce the dispersion effect and is simple to manufacture, with a compact structure, eliminating winding, vias and corresponding parasitic source inductance, reducing the radiation loss caused by surface waves, and increasing the antenna gain; it has high isolation and notch characteristics; it uses economical FR4 material, is small in size, and has a simple overall antenna structure and is easy to process.