107 results about "Transmission line transformer" patented technology

When an output electrode of a power transistor in the final amplifying stage is coupled to a transmission line transformer TLT serving as an impedance matching circuit, a condition for impedance matching of the transmission line transformer is maintained. An RF amplifying device comprises a transmission line transformer coupled to an output electrode of a power transistor for generating transmission power to be fed to an antenna. The transmission power from the output electrode of the power transistor is fed to one end of a main line of the transmission line transformer, and one end of a secondary line of the transmission line transformer is coupled to an AC grounding node. The other end of the secondary line is coupled to the one end of the main line, thereby generating the transmission power to be fed to the antenna from the other end of the main line. At an energy coupling part where the main line of the transmission line transformer is in close proximity of, and opposite to the secondary line, coupling energy is transmitted from the secondary line to the main line. Coupling members electrically coupled to the output electrode of the power transistor are electrically coupled to a joint formed in either the main line, or the secondary line, at part of the energy coupling part.

A broadband loaded antenna and matching network with related methods for design optimization are disclosed. The loaded antenna structures may preferably be either monopole or dipole antennas, but the particular methods and techniques presented herein may be applied to additional antenna configurations. The load circuits positioned along an antenna may comprise parallel inductor-resistor configurations or other combinations of passive circuit elements. A matching network for connecting an antenna to a transmission line or other medium preferably includes at least a transmission line transformer and a parallel inductor. Various optimization techniques are presented to optimize the design of such broadband monopole antennas. These techniques include implementation of simple genetic algorithms (GAs) or micro-GAs. Component modeling for selected components may be effected through either lumped element representation or curved wire representation. Measured results are presented to ensure that certain design criteria are met, including low voltage standing wave ratio (VSWR) and high gain over a desired frequency band.

The invention discloses an active broadband matching method of a short-wave frequency-band electrically small antenna and a matching circuit thereof, the electrically small antenna is matched by a non-Forster reactive element and a passive broadband matching network, the non-Forster reactive element is realized by a negative impedance converter, the negative impedance converter and the passive broadband matching network are cascaded into an active broadband matching network with two ports, one port of the matching network is connected with the electrically small antenna, and said two ports are connected with an emitter/receiver. In the invention, the non-Forster reactive element and the passive broadband matching network are comprehensively considered, led loss is regulated in realization process of the non-Forster reactive element, single traditional negative capacitor can be replaced by in series connecting a negative capacitor and a negative inductor to better neutralize the impedance imaginary part, a transmission line transformer is led into the matching network, and the deviation between a testing value and a design value can be compensated by slightly adjusting the transformation ratio of the transmission line transformer.

A composite transmission line transformer includes at least one core, a first port, a second port, and one or more pairs of transmission lines wound about the core(s). Each transmission line is in signal communication with the first port and the second port. For each pair, the transmission lines are interconnected in series at the first port and at the second port such that the first port and the second port are DC-isolated from each other.

A transmission line transformer is disclosed. The transformer improves efficiency and a dynamic range of a power amplifier. The transformer is formed to have a plurality of load impedances as the primary side of the transmission line transformer is separated to form a plurality of primary transmission lines with parasitic components which are different from each other. The transformer is used as an impedance matching circuit of the power amplifier requiring a plurality of load impedances.

The invention discloses a high-precision zero drift compensation circuit for an analog multiplier. The influence of zero drift on the analog multiplier is compensated. The high-precision zero drift compensation circuit comprises the analog multiplier, a transmission line transformer, a reference power supply, a zeroing resistor, a grounding resistor and a temperature sensor, wherein the transmission line transformer is connected to the input end of the analog multiplier, and is used for reducing the influence of biasing current at the input end on the analog multiplier; and fixed voltage is applied to the zeroing end of the multiplier through the reference power supply, the zeroing resistor and the grounding resistor in a voltage share manner to compensate the biasing voltage at the output end. The grounding resistor with a low resistance value is used for reducing the influence of the biasing current at the zeroing end on the analog multiplier; and compensation voltage of which the temperature excursion size is equal to that of the multiplier and the direction is opposite to the direction of the multiplier is formed at the zeroing end of the multiplier through the temperature sensor and the grounding resistor, so that the influence of the temperature excursion on the analog multiplier is reduced effectively. The high-precision zero drift compensation circuit has a simple structure; and suppression to the zero drift of the analog multiplier is improved by an order of magnitude.

The invention provides a broadband quadrature phase shifter which comprises a first transmission line transformer, a second first transmission line transformer, a first capacitor, a second capacitor, a first resistor and a second resistor; two secondary windings of the first transmission line transformer are connected end to end and grounded; two secondary windings of the second transmission line transformer are connected end to end and grounded; the upper end of the primary winding of the first transmission line transformer is grounded; the lower end of the primary winding of the second transmission line transformer is grounded; the primary winding of the first transmission line transformer is connected with the first capacitor and the first resistor in series in sequence to form a closed loop, and the sharing end of the first capacitor and the first resistor is connected with the first output end of the quadrature phase shifter; the secondary windings of the second transmission line transformer are connected with the second capacitor and the second resistor in series in sequence to form a closed loop, and the sharing end of the second capacitor and the second resistor is connected with the second output end of the quadrature phase shifter. Due to transmitting signals of wide frequency range, the transmission line transformers can be used as phase inverter circuits to realize quadrature phase shift of broadband signals.

The invention provides a 30MHz-512MHz multi-band 2.5m whip antenna, which mainly solves the impedance matching problem between the antenna and the radio station. The entire antenna includes: a radiator, a coaxial cable 18, and a base 6. The radiator adopts a combined structure of a lower radiator 7 and an upper radiator 5. The lower radiator includes a lower copper tube 1 and an upper copper tube 3, two copper tubes The tubes are connected by a transmission line transformer 2, and a radiation oscillator 4 is fixed in the upper copper tube to form a sleeve antenna structure. The transmission line transformer adopts a three-winding center tap, and is equipped with four coils, which are respectively connected to the inner conductor, outer conductor, upper section copper tube, and lower section copper tube of the coaxial cable. It is used as both an electronic switch and an impedance matching element. Ultra-wideband characteristics in the 30MHz~512MHz frequency band. The invention has the advantages of wide frequency band, small standing wave ratio, high gain, no need for tuning, and can be directly matched with radio stations, and is suitable for installation on various armored vehicles and ships.

An example of a transmission-line transformer may include a transmission-line assembly and a balun assembly. The transmission-line assembly may include first and second conductors forming at least first and second transmission-line sections. The transmission-line assembly may provide a signal path through the first conductor and second conductor in series to a circuit ground. Balanced lines of the balun assembly may be connected to respective intermediate points on the first and second conductors between the first and second transmission-line sections. The transmission-line transformer may provide a signal path between a first end of the first conductor of the transmission-line assembly and the unbalanced line of the balun assembly.

The invention relates to a module for separating a different-mode signal and a common-mode signal. The module comprises a first transmission-line transformer. The two ends of a first transmission-line transformer primary coil are connected with the firing line output terminal and the null line output terminal of a line impedance stabilizing network respectively, the first transmission-line transformer primary coil is connected between the firing line output terminal and the null line output terminal, a center tap is arranged in the middle of the primary coil, the center tap is grounded through a first resistor, the center cap is connected with a common-mode signal output terminal, the firing line output terminal is further connected with one end of the input end of a second transmission-line transformer, the corresponding output end of the second transmission-line transformer is connected with a different-mode signal output terminal through a second resistor, the null line output terminal is further connected with the other end of the input end of the second transmission-line transformer, and the corresponding output end the second transmission-line transformer is grounded. The module has the advantages of being simple in circuit structure, good in common-mode rejection ratio and different-mode rejection ratio, precise in test effect, small in size, light in weight and the like.

A dual output autotransformer is realized by employing a novel topology in which three transformers are wound on a single, high permeability, ferrite, binocular core. The three transformers are (1) an autotransformer; (2) a coupled winding to the autotransformer; and, (3) a transmission line transformer. Within the topology employed, the outputs of the coupled line transformer and the transmission line transformer provide the balanced output (secondary) and the input to the autotransformer forms the unbalanced primary. Such an approach results in a wideband response of from 30 MHz to 3000 MHz or greater with the requisite amplitude and phase balance.

The invention discloses a modularized solid state nanosecond pulse generator structure based on a PCB Blumlein transmission line and a transmission line transformer. The generator is combined with the characteristics that the Blumlein transmission line is liable to form a high-frequency nanosecond narrow pulse and the transmission line transformer is good in high-frequency characteristics. The generator employs a modularized structure design, and each module generates a primary pulse through Blumlein and the primary pulse is amplified and outputted to a load. A plurality of modules are in cascading connection for output, thereby increasing the voltage amplification factor, and increasing the output power. Meanwhile, because the modularized design is employed, the impedance transformation ratio of the transmission line transformer is also reduced, and the generator is more suitable for a small-impedance load. A microstrip line is used in the design for the design of a transmission line, and the impedance matching design can be carried out according to the size of a load. Meanwhile, the size of the generator is greatly reduced, and the compact design is achieved. Meanwhile, the generator employs an MOS tube as a switch, thereby facilitating the control of the generator, and achieving the convenient adjustment of the amplitude value and frequency.

The invention provides a broadband triple-circuit synthetic radiofrequency microwave power amplifier, comprising an in-phase distribution circuit connected to a radiofrequency input end, three intermediate conversions circuits and an unbalanced transmission line transformer connected to a radiofrequency output end; each of the three intermediate conversion circuits is connected in parallel and then connected respectively to the in-phase distribution circuit and the unbalanced transmission line transformer; each intermediate conversions circuit comprises an input bias matching circuit, a radiofrequency microwave push-pull transistor, an output feed matching circuit, a balanced transmission line transformer and a transmission line balun; the input end of each intermediate conversion circuit is connected in parallel through its input bias matching circuit and then connected to the in-phase distribution circuit; the output end of each intermediate conversion circuit is connected in parallel through its transmission line balun and then connected to the unbalanced transmission line transformer. The power amplifier can convert synthetic and load lines, the circuitry is simple, great bandwidth and space saving are achieved finally, and the power amplifier is suitable for radiofrequency and microwave low-frequency terminals.

The invention discloses a mobile nanosecond pulse ablation instrument. The instrument comprises a cabinet body provided with universal wheels at the bottom, and is characterized in that a pulse generation system for generating nanosecond pulses is arranged inside the cabinet body, and a pulse output system for delivering the nanosecond pulses to a load is arranged outside the cabinet body; the pulse output system comprises a rocker arm fixed on the cabinet body and an electrode needle junction box fixed with the tail end of the rocker arm, and an electrode needle is arranged on the electrode needle junction box; a transmission line transformer is arranged in the rocker arm; one end of the transmission line transformer is electrically connected with the output end of the pulse transmissionsystem, and the other end is electrically connected with the electrode needle junction box. The ablation instrument can be directly used in the nanosecond pulse electric field ablation process, and has the advantages of convenient use, compact structure and good application prospect.

The invention discloses a P-band high power amplifier device, and relates to a power amplifier device of a P-band signal channel portion in the communication field. The P-band high-power amplifier comprises a propelling-stage power amplifier, a last-stage power amplifier, a switch controller, a power supply, a cooling unit, a monitoring interface and a circulator. In the P-band high power amplifier device, a modularization technology, an integration technology, a thermal design technology and a transmission line transformer technology are adopted to finish high-power synthesis, and the size is relatively small. The P-band high power amplifier has the functions of low-power protection, thermal protection and reflecting protection; the P-band high power amplifier device further has a rapid switching function and a very large switch-off depth, and is particularly suitable to be taken as a power amplifier device in a P-band half-duplex communication system.