Abstract: There is provided a frequency Selective Surface (FSS) structure for multi frequency bands configured with unit cells, each including a loop unit, arranged at regular intervals, wherein each unit cell includes: a dielectric layer; and the loop unit having a fixed width and formed on the dielectric layer, wherein the loop unit includes a first loop and a second loop formed inside the first loop with a predetermined space away from the first loop, each of the first loop and the second loop being formed sinuously in at least one portion.

Abstract: The present invention relates to an antenna system mounted on a mobile vehicle. In the present invention, a power distributor and a part of a high-frequency module that includes a frequency converter are placed in an external fixed unit that is placed outside a radome. In addition, an active cooler/cooling fin, a heater, and an air circulation fan are placed at an internal bottom plane of the antenna system, and a cooling fin and cooling fan are placed at an external bottom plane of the antenna system.

Abstract: Provided is a RF switch for switching a path of a RF signal using a semiconductor transistor such as a field effect transistor (FET). The RF switch includes a plurality of resonators connected to a RF transmission line, and at least one of switching elements connected in shunt or in series between the plural of resonators. The plurality of resonators resonate by interacting with the switching elements when the switching elements are shorted or open.

Abstract: Provided is a resonator filter using conductive plates having a curved surface to connect an input/output coaxial connector to a resonator. The resonator filter includes: a plurality of resonators for resonating; an input/output coaxial connector; an input/output supporting unit formed between the input coaxial connector and one of the resonators and/or between an output supporting unit formed between the output coaxial connector and other resonator for electrically and mechanically supporting the input/output coupling; and a connecting unit for connecting the input/output supporting unit and the input/output coaxial connector, wherein the input/output supporting unit is a conductive plate with a curved surface having a center axis similar to the resonators.

Abstract: An ultra wideband hermetically sealed surface mount package for a microwave monolithic integrated circuit (MMIC) is provided including: an integrated circuit; a package body being mounted with the integrated circuit and comprising a plurality of first dielectrics formed in a multilayer, a first line unit mounted to a circuit substrate and is electrically connected with an external circuit, a second line unit upwardly extended from the first line unit and is electrically connected with the first line unit, a third line unit extended to the right angle from the second line unit and is electrically connected with the second line unit, and a bonding unit that electrically connects the third line unit and the mounted integrated circuit; and a package cover being formed on the package body to seal the integrated circuit and comprising a plurality of second dielectrics formed in a multilayer.

Abstract: A coupled line filter includes: a first line resonator connected input port and a second line resonator connected with output port each having an electrical length of 270° at a predetermined center frequency, the first and second line resonators being disposed parallel to each other; and a third line resonator including one or more line resonators disposed between the first line resonator and the second line resonator, each line resonator having an electrical length of 90° at the center frequency and a first side aligned with first sides of the first line resonator and the second line resonator, wherein an order of the coupled line filter is determined by summing the number of the line resonators included in the third line resonator and the first and second line resonators.

Abstract: This research discloses an ultra wideband system-on-package (SoP). The SoP includes a package body; a first integrated circuit mounted on the package body; a first signal transmission unit connected to the first integrated circuit; a signal via connected to the first signal transmission unit and including a slab line and a trough line; and a second signal transmission unit connected to the signal via. The technology of the present research can transmit ultra broadband signals by minimizing discontinuity of signals appearing during vertical transition that occurs in the course of a signal transmission to/from an external circuit, and a fabrication method thereof.

Abstract: Provided are a low-temperature-cofired-ceramic (LTCC) package and a method of manufacturing the same. The LTCC package includes: an LTCC substrate including a plurality of LTCC layers and a recess in which a device is mounted; a thermal conductive element adhered onto a first LTCC layer exposed by the recess using a first thermal conductive adhesive member; the device adhered onto the thermal conductive element using a second thermal conductive adhesive member; and a connection member for electrically connecting the device with the LTCC substrate. In the LTCC package and the method, portions of the LTCC layers disposed under a high-heating device except a lowermost LTCC layer contacting a heat sink, which correspond to a thermal transmission path, are removed and replaced by a higher thermal conductive material to minimize heat dissipation resistance and heat resistance caused by thermal conduction.

Abstract: Provided is a high-power device having a thermocouple (thermoelectric couple) for measuring the temperature of a transistor constituting a high-power device. The high-power device includes a heating element, a thermocouple formed adjacent to the heating element, and a dielectric body formed between the heating element and the thermocouple.

Abstract: A broadband active balun using reactive feedback and a balanced mixer using the balun are provided. The broadband active balun comprises a common gate FET having a source connected to an input terminal, a gate connected to the ground, and a drain connected to a first output terminal; a reactive impedance element having one end connected to the drain of the common gate FET and the other end connected to one of the gate and the source of the common gate FET, and a common source FET having a gate connected to the input terminal, a source connected to the ground and a drain connected to a second output terminal. Accordingly, the active balun has a small physical size and a wide frequency band.

Abstract: A realization method of a multiple passband filter that equalizes a group delay without using an external equalizer is disclosed. The realization method includes the steps of: a) calculating a transfer function based on poles and zeros; b) extracting an input/output coupling coefficient and a coupling matrix from the calculated transfer function as a network parameter; and c) physically designing and realizing elements of the filter to have the extracted network parameter.

Abstract: Provided is a digital attenuation apparatus having ultra broadband and excellent attenuation characteristics. The digital attenuation apparatus includes an input port, an output port, a first transmission line, a second transmission line, a first switching device, a third transmission line, a first resistive element, a second resistive element, a fourth transmission line, a second switching device, a fifth transmission line, and a third resistive element.

Abstract: A tuning assembly for a radio frequency is disclosed. The tuning assembly includes: a tuning screw grasping unit integrally formed with a main body of the filter, which includes a tuning screw receiving unit and a fastening member for grasping a tuning screw; and a tuning screw inserted into the filter through the tuning screw receiving unit, wherein the filter is finely tuned by inserting the tuning screw into the filter through the tuning screw receiving unit and a female screw unit formed at the filter.

Abstract: Provided is a digital attenuation apparatus having ultra broadband and excellent attenuation characteristics. The digital attenuation apparatus includes an input port, an output port, a first transmission line, a second transmission line, a first switching device, a third transmission line, a first resistive element, a second resistive element, a fourth transmission line, a second switching device, a fifth transmission line, and a third resistive element.

Abstract: Provided is a resonator filter using conductive plates having a curved surface to connect an input/output coaxial connector to a resonator. The resonator filter includes: a plurality of resonators for resonating; an input/output coaxial connector; an input/output supporting unit formed between the input coaxial connector and one of the resonators and/or between an output supporting unit formed between the output coaxial connector and other resonator for electrically and mechanically supporting the input/output coupling; and a connecting unit for connecting the input/output supporting unit and the input/output coaxial connector, wherein the input/output supporting unit is a conductive plate with a curved surface having a center axis similar to the resonators.

Abstract: A waveguide diplexer having an electric plane T-junction structure with a resonant iris is disclosed. The waveguide includes: a waveguide having a predetermined shaped cross section; a transmitting filter for preventing to generate a harmonic band and a higher mode in a receiving band by changing impedance to have a low pass characteristic inside the waveguide; a receiving filter for minimizing an insertion loss by changing impedance to have a bandpass characteristic inside the waveguide; an electric plane T-junction for isolating/combining a transmitting signal and a receiving signal without electric interference by connecting the transmitting filter and the receiving filter, and minimizing interference of a frequency transmitted/received through the transmitting filter and the receiving filter; and an impedance converter for differentiating a transmitting port and a receiving port with minimum electric interference to the transmitting filter and the receiving filter by changing the impedance.

Abstract: The present invention relates to a microwave variable attenuator variably attenuating while maintaining a matching state. The microwave variable attenuator includes: an input terminal for inputting a microwave signal; an output terminal for outputting a microwave signal; a control voltage supplying unit for supplying a control voltage; an input terminal matching unit for matching an impedance of the input terminal in response to the control voltage; an output terminal matching unit for matching an impedance of the output terminal in response to the control voltage; and an attenuating unit for attenuating the microwave signal inputted to the input terminal based on an attenuation controlled according to the control voltage and outputting the attenuated microwave signal, wherein the attenuating unit includes a pin diode and a resonant inductor connected each others in parallel for resonating an effect of a parallel capacitance.

Abstract: Provides is a screwdriver-and-nut wrench-combined tuning tool for radio frequency filter which is capable of preventing a movement of a tuning screw occurred when locking it with a tuning nut by making their combined body, preventing a difficulty of tuning resulted due to a separate use of a screwdriver and a nut wrench when a space for access to a tuning unit is not sufficient, and minimizing an interruption of turns of the tuning screw and the tuning nut by locking or turning the screwdriver and the nut wrench independently. The screwdriver-and-nut wrench-combined tuning tool for radio frequency filter comprises a case, a nut wrench positioned to rotate inside the case for turning or holding a tuning nut, a screwdriver positioned to rotate inside the nut wrench for turning or holding a tuning screw, a nut wrench locking unit that is fitted to the nut wrench or the case for locking the nut wrench; and a screwdriver locking unitthat is fitted to the case for locking the screwdriver.

Abstract: A tuning assembly for a radio frequency is disclosed. The tuning assembly includes: a tuning screw grasping unit integrally formed with a main body of the filter, which includes a tuning screw receiving unit and a fastening member for grasping a tuning screw; and a tuning screw inserted into the filter through the tuning screw receiving unit, wherein the filter is finely tuned by inserting the tuning screw into the filter through the tuning screw receiving unit and a female screw unit formed at the filter.

Abstract: Provides is a screwdriver-and-nut wrench-combined tuning tool for radio frequency filter which is capable of preventing a movement of a tuning screw occurred when locking it with a tuning nut by making their combined body, preventing a difficulty of tuning resulted due to a separate use of a screwdriver and a nut wrench when a space for access to a tuning unit is not sufficient, and minimizing an interruption of turns of the tuning screw and the tuning nut by locking or turning the screwdriver and the nut wrench independently. The screwdriver-and-nut wrench-combined tuning tool for radio frequency filter comprises a case, a nut wrench positioned to rotate inside the case for turning or holding a tuning nut, a screwdriver positioned to rotate inside the nut wrench for turning or holding a tuning screw, a nut wrench locking unit that is fitted to the nut wrench or the case for locking the nut wrench; and a screwdriver locking unitthat is fitted to the case for locking the screwdriver.