7results about How to "Low return loss" patented technology

The utility model relates to a filter circuit, a dielectric filter and a duplexer, and the filter circuit comprises a signal input end which is used for inputting a signal; the signal output end is used for outputting a signal; the resonance unit comprises a plurality of resonance circuits which are sequentially arranged between the signal input end and the signal output end in parallel; the coupling inductor unit is arranged between the signal input end and the grounding end and between the signal output end and the grounding end, and the coupling capacitor unit is arranged between the signal input end and the first resonance circuit and between the signal output end and the last resonance circuit. According to the utility model, the problem of large return loss in an ultra-wide passband can be solved, standing waves are effectively improved, the working efficiency of the filter is improved, and the communication effect is improved. The dielectric filter is connected with the grounding silver layer on the outer surface of the ceramic substrate through leading out a first connecting line and a second connecting line from the input port and the output port respectively, and plays a role of equivalent inductance.

The invention provides a broadband gain positive slope amplitude-phase control multifunctional chip for a T / R assembly, which relates to the technical field of radio frequency integrated circuits and comprises a receiving channel, a transmitting channel, an equalization circuit, a numerical control attenuator, a numerical control phase shifter, a transmitting-receiving change-over switch module and a parallel control module. The parallel control module is used for outputting parallel control signals to the numerical control attenuator, the numerical control phase shifter and the transceiving change-over switch module; the equalization circuit is respectively connected with the receiving channel and the transmitting channel through the transmitting-receiving change-over switch module, so that a signal path of the receiving channel and a signal path of the transmitting channel multiplex the equalization circuit, the numerical control attenuator and the numerical control phase shifter; and the equalization circuit is of an on-chip integrated structure and is used for adjusting the gain of the receiving channel and the gain of the transmitting channel to present a positive slope characteristic relative to the frequency in a wide frequency band so as to compensate the frequency attenuation of an external device.

This utility model belongs to the field of filters, specifically a coaxial-to-waveguide filter, including a cavity with a waveguide port on the inner side. A coaxial connector is bolted to the top side of the waveguide port. Multiple resonant cavities are formed inside the cavity, and a coupling grounding post is installed inside the cavity through the resonant cavities. A coupling conductor is fixed between the waveguide port and one of the resonant cavities through a supporting insulating medium. One end of the coupling conductor is soldered to the coupling grounding post in the corresponding resonant cavity, and the other end extends into the waveguide port, realizing bidirectional coupling transmission of electromagnetic waves. This utility model introduces cross-coupling technology inside the filter, which significantly improves the out-of-band suppression compared to relying on natural attenuation, reduces the number of resonant cavities required to achieve the same suppression, thereby effectively reducing the product size and also reducing the filter insertion loss. This device achieves low port return loss through high out-of-band suppression.

The utility model relates to the technical field of communication, in particular to a built-in FPC (Flexible Printed Circuit) antenna for tunable broadband. The utility model provides a tunable broadband built-in FPC antenna, which comprises a dustproof layer, an electromagnetic shielding cover, a wire end and the like, the electromagnetic shielding cover is arranged on the lower side of the dustproof layer, and the dustproof layer is connected with the wire end. Through the design of integrating a plurality of switchable inductance elements, dynamic tuning and accurate matching of the resonant frequency of the antenna are realized, not only is the adaptive capacity of the antenna under different frequency bands enhanced, but also the working bandwidth of the antenna is effectively widened, and the requirements of a modern communication system for multi-frequency band, high integration level and intelligent tuning are met; low return loss can be realized in a target frequency band, and the matching performance of the antenna and a transmission line and the signal transmission efficiency are improved; the method adapts to a wide frequency band range, and the performance of multiple frequency points is good; the structure is convenient to realize, manufacturing and integration are facilitated, cost is reduced, and the antenna can be widely applied to internet of things 4G antenna projects such as power banks and water meters.

The application provides a miniaturized low-profile dual-polarized microstrip antenna, an antenna assembly and a PDA device, the microstrip antenna comprising at least one guiding layer, a ground layer and a radiation layer arranged in parallel and spaced apart from top to bottom, the radiation layer adopting a coaxial transmission line direct feeding structure, the advantage of the direct feeding structure being that the coaxial line feeding is directly used to save the complicated power division and phase shift structure, the radiation efficiency can be improved and the loss can be reduced; wherein the guiding layer is a first metal floor, the ground layer is a second metal floor, and the radiation layer comprises four dipole units in a cross distribution at a central position, the antenna structure enables the microstrip antenna to use air as a propagation medium, the speed of electric signal propagation is inversely proportional to the square root of the dielectric constant, when the dielectric constant is lower, the signal transmission speed is faster, therefore, the application uses air medium to transmit signals, the signal transmission speed can be accelerated, and the label reading efficiency is improved.

The utility model discloses a compact one-to-four power divider, which adopts a two-stage symmetrical branch circuit design, filters through parallel grounding capacitors at input ports, and optimizes input matching characteristics. The first-stage branch circuit realizes impedance matching and inhibits electromagnetic coupling between branches by using a spiral inductor, an isolation capacitor and a resistance network; the secondary branch circuit compensates ultrahigh frequency signal phase and amplitude deviation through a matched transmission line and a minimum grounding capacitor (multiple small-specification capacitors are connected in series), and the isolation degree of an output port is further improved by combining an isolation resistor. Through symmetric frequency division and impedance matching technologies, the power divider realizes balanced distribution of signal amplitude and phase within the frequency band of 6-18GHz, significantly reduces return loss and insertion loss, improves branch isolation to more than 20dB, effectively solves the crosstalk problem in a multi-channel system, and improves the performance of the multi-channel system. And the requirements of scenes such as high-frequency-band wireless communication and radar detection on low-loss, high-isolation and broadband signal distribution are met.

A method for forming an optical device includes: providing a substrate, the substrate including a first substrate, a buried oxide layer on the first substrate, and a second substrate on the buried oxide layer; forming an initial third waveguide and a corresponding initial third groove in the second substrate, the initial third waveguide including an initial third starting region; forming a first dielectric layer in the initial third groove and on the initial third waveguide; removing part of the first dielectric layer and part of the initial third waveguide to form a third waveguide and a corresponding third groove in the second substrate, the third waveguide including a third starting region, a projected area of the third starting region on a surface of the substrate being smaller than a projected area of the initial third starting region on the surface of the substrate. The formed optical device can effectively reduce return loss.