Abstract: A dual frequency antenna with wide frequency includes an inner radiator in helical structure, which is electrically connected with a host by a feeding point of the host, and an outer radiator in helical structure in which the inner radiator is packed. The inner radiator includes a first radiating unit located at the lower part for generating resonance and a second radiating unit located at the upper part. The resonant frequency of the second radiating unit is higher than that of the first radiating part; the height of the helical structure of the outer radiator is less than the total height of the inner radiator. The performance of dual frequency antenna can better focus on the upper hemisphere, and the bandwidth of the dual frequency antenna is wider in the ultra high frequency (UHF) frequency band.

Abstract: The present invention relates to a private network communication technology, and it provides an implementation method, terminal, relay station and system for DMR private communication with respect to the existing defects that each of the communication terminals can only communicate with each other by using the same time slot in a group, and thereby a frequency width of 12.5 KHz can not be used sufficiently. The DMR private network communication terminal includes a communication module for receiving CACH information, receiving and transmitting DMR private network communication, a synchronization module for establishing synchronization and determining which time slot the received DMR private network communication occupies based on the received CACH information; and controlling the communication module to make a response for the received DMR private network communication in the time slot.

Abstract: The present invention relates to communication technologies and provides a private network communication terminal and a method for realizing private network communication, In the invention, one private network communication can only be performed in one time slot with a fixed location in a DMR TDMA frame, so that other mobile communication terminals that do not participate in the private network communication can determine an unoccupied time slot in advance, thereby they can initiate a new private network communication with the unoccupied time slot.

Abstract: The present invention provides a method for implementing a radiophone based conference call and dynamic grouping, which generally includes selecting a dynamic grouping function and members of an intended group through a man-machine interface of a radiophone, generating a control packet in a coding format and an extensible interface, the coding format and the extensible interface being inherent to a preset protocol stack module, and then transmitting the control frame in a control frame to a corresponding receiving end, and the receiving end upon reception of the control frame decodes the control frame and initiates a frequency modification module to modify frequency modification information by adding the group ID of the intended group. The radiophone in the present invention can perform a scheduling function, and time can be saved in an emergency for rapid and convenient dealing with an incident.

Abstract: The present invention relates to a radio with a key and knob combination. To solve problems such as inconvenience caused by the independent PTT key and volume control knob on the traditional radios, the present invention provides a radio with a key and knob combination, comprising a PPT key unit and a volume control unit, wherein the key is installed inside a central cavity of the knob, which is a hollow knob, to form the key and knob combination. Rotation of the knob (106) may drive the shaft (102) and the toggle piece (111) to rotate synchronously, and then toggle the volume switch (112), while the pressed key (101) may cause the shaft (102) moving axially to toggle the PTT switch (103). When operating the radio with a single hand, users can both press the PTT key to initiate a call and rotate the knob to adjust the volume level by a thumb or a forefinger, and the operation is very convenient.

Abstract: A connector comprises a connector body (40), a connector upper housing (10), a locking component (20) and a connecting assembly (30) provided within the connector body (40). The locking component (20) includes a locking knob (23) and a locking bolt (21). Holes are provided on the middle of the connecting assembly (30) and the connector body (40) respectively to match with the locking bolt (21). The diameter of the locking knob (23) of the locking component (20) is larger than the width of the connector body (40). The connector upper housing (10) is fixed on the connector body (40) and restricts the locking knob (23) between the connector body (40) and the connector upper housing (10).