3results about How to "Low spurious" patented technology

The invention belongs to the technical field of precision measurement, and particularly relates to a power supply system for reducing low-frequency spurious signals of a measuring instrument and a phase compensation method, which comprise three stages of power supply loops, the first stage is used for completing conversion of AC-DC (Alternating Current-Direct Current) DC bus voltage, and the second stage is used for completing conversion from the DC bus voltage to each path of required voltage and low-pass filtering. And in the third stage, active rate filtering of various power supplies is realized through the LDO, and the power supplies are output to each whole device for use. An innovative multi-channel coherent clock output phase compensation algorithm is used, each channel of clock output phase of an external reference clock synchronization circuit is optimized, clock phases of power supply conversion circuits are different, multi-channel same-frequency clock spurious signals and harmonic waves thereof are enabled to generate incoherent offset, and space radiation interference of low-frequency spurious signals is reduced.

The invention relates to the technical field of radio frequency electronics, and discloses a multi-channel radio frequency signal source device and an implementation method, and the device comprises a satellite receiver, a frequency reference source, a clock signal source, a multi-channel radio frequency signal source, a frequency monitoring module and a phase monitoring module. The frequency reference source locks a satellite signal generation benchmark; the clock signal source generates a driving clock based on a reference; the multi-path radio frequency signal source generates multi-path radio frequency signals by using a driving clock based on a direct digital frequency synthesis principle; the phase monitoring module measures signal phase difference through IQ phase discrimination and feeds back the signal phase difference, and realizes closed-loop phase locking in cooperation with multiple paths of radio frequency signal sources. A two-stage driving framework is adopted, synchronous frequency modulation of multiple paths of signals can be achieved by adjusting a clock, the phase relation is not changed, and automatic phase recovery after independent frequency modulation can be achieved through phase compensation. The invention has the advantages of continuous frequency modulation phase, stable amplitude, no need of automatic level control, low phase noise, high phase resolution and the like.

The utility model provides a kind of multiple folding optical display system and wearable equipment of thinning and lightening belong to optical imaging technical field, including display unit, first optical element, second optical element, third optical element, fourth optical element and fifth optical element;First optical element is set on the light path of display unit;Second optical element is set on the transmission light path of first optical element, third optical element is set on the front side of second optical element;Fourth optical element is set on the front side of third optical element, and the front surface of fourth optical element is Fresnel surface;Fifth optical element is set on the back side of second optical element, and there is polarized light splitting element between the front surface of fifth optical element and the back surface of second optical element.It is compact in structure, small in size, thin in thickness, light in weight, low in stray, good in imaging quality, large in field of view angle, greatly improves the experience of user.