Abstract: The invention is directed to a method for matching characteristic impedances in a wideband manner. The matching of characteristic impedances is realized by tapering a conductor inside a wall composed of a dielectric material. The tapered conductor is either an asymmetric stripline or an asymmetric coplanar line. The method enables characteristic impedance matching at up to 40 GHz. The coupler is applicable to signal line feedthroughs in MMIC packages.

Abstract: A stripline integrated circuit apparatus comprising a first ground plane, a stripline section positioned on the first ground plane, the stripline section including N stripline regions where N is a whole number greater than or equal to one, wherein each stripline region includes a stripline sandwiched therebetween a first dielectric layer with a thickness and a second dielectric layer with a thickness where each adjacent stripline is connected in parallel, wherein each adjacent stripline region is separated by a ground plane, a second ground plane positioned on the stripline region, and wherein the plurality of stripline sections are formed and electrically connected in series. The distances between the striplines and the ground planes are adjusted to vary the input and output impedance.

Abstract: Systems, methods, and probe devices for electronic monitoring and characterization using absorbent media confined by a metallic mesh. The mesh allows a stream of liquid or gas to pass through the structure, so that the media will adsorb the material to which it is specific. This changes the permittivity of the media in which the electromagnetic field is propagating. This change in permittivity can be seen through the use of classical microwave methods such as phase shift, amplitude changes, frequency changes in a cavity or the frequency of an unbuffered oscillator. Some embodiments use a two cylinder structure, where an outer cylinder contains a material which selectively removes a chemical which may be in conflict with or would contaminate the sensing of the desired chemical. This outer cylinder does not play a part in the measurement because it is outside the metal shield which contains the measurement adsorbent, and is thus outside the electromagnetic field.

Abstract: A signal transmission unit includes a first transmission line, a second transmission line, and a tapered transmission line coupling the first transmission line to the second transmission line. The tapered transmission line has a width and a length and the width changes along the length according to one or more functions. The one or more functions include but are not limited to linear functions, non-linear functions, hyperbolic functions, and exponential functions.

Abstract: A probe whose characteristic impedance can be accurately adjusted to a desired value with the production of a small number of prototypes. The probe includes a first line with a signal terminal to be connected to a signal electrode of a circuit to be measured and at least one first region connected to the signal terminal and to which one end of a chip capacitor is connected, a second line connected to a terminal of the first line and a junction to be connected to a measuring instrument at the remaining terminal, and an impedance matched to a characteristic impedance of the measuring instrument, a ground connector with a ground terminal to be connected to the ground electrode of the circuit to be measured, and at least one second region connected to the ground terminal and on which the remaining terminal of the chip capacitor is mounted in one-to-one correspondence with the first region.

Abstract: In a package for integrated circuits, a signal transmission line has a first segment closer to the chip that is bracketed vertically by ground planes at a first vertical distance and a second segment further from the chip that is bracketed vertically by ground planes at a second vertical distance greater than the first distance, with an aperture being formed in the ground planes at the first distance, so that those ground planes do not interfere with the impedance set by the second set of ground planes.

Abstract: A surface-mountable mm-wave signal source is provided. The surface-mountable mm-wave signal source comprises: a conductive metal base; a mm-wave signal source disposed over an upper portion of the metal base; a first radio frequency transmission line carrying a quasi-TEM signal from the mm-wave signal source, which is disposed over an upper portion of the metal base and proximate the signal source; a first mode transformer at least partially integrated into the upper portion of the metal base to convert the quasi-TEM signal carried by the planar transmission line into a rectangular waveguide mode signal; a waveguide well having upper and lower ends disposed within the base for carrying the rectangular waveguide mode signal from an upper portion of the base to a lower portion of the base; and a second mode transformer at least partially integrated into the lower portion of the base to convert the rectangular waveguide mode signal to a quasi-TEM signal within a second radio frequency transmission line.

Abstract: A high frequency apparatus includes a dielectric substrate having a surface including a first area and at least one second area; a first dielectric thin layer provided on a portion of a first area; and a uniplanar transmission line provided on the first dielectric thin layer and on a portion of the second area, the uniplanar transmission line extending, continuously on the second area and the first dielectric thin layer.

Abstract: A multilayer ceramic device (100) includes a plurality of dielectric layers (104A-G) separated by ground planes (114) and includes a plurality transmission line segments (118) in generally folded configuration for defining a tapered transmission line (102). The profile of the transmission line may vary and includes such profiles as embodied in the depicted lines (200, 206, 212).

Abstract: A method for fabricating a microstrip package to optimize signal trace impedance control is disclosed. The method includes patterning a plurality of signal traces on a multilayer substrate, and patterning a plurality of guard traces on the multilayer substrate, that are interspersed alternately among the signal traces to provide noise shielding between the signal traces. In a further embodiment, the traces are patterned on the substrate with a width that is adjusted at different locations based on the presence the guard traces to enable the package to meet a particular impedance requirement.

Abstract: An AC power feed device for conducting electrical power from a source to a load. The feed device has a constant characteristic impedance along its length and an outer periphery that varies in size progressively along its length, or the feed device has an input end connected to the match network and an output end connected to an electrode, and has a characteristic impedance which varies from a value substantially equal to the output impedance of a match network coupled at the input end to a value equal to the impedance of the electrode.

Abstract: A microstrip termination is provided with a thin film resistor connecting a transmission line to a tapered edge ground, enabling high frequency performance, such as for optical modulators. The tapered edge ground is formed with metal deposited on a substrate edge between a top surface of a substrate containing the transmission line with thin film resistor, and a bottom surface with a metal coating forming a ground plane. The tapered edge is cut at an angle in the range of 30 degrees with respect to the top surface. The microstrip termination provides a wider bandwidth of impedance matching than a standard microstrip termination.

Abstract: A millimeter wave system includes a plurality of millimeter wave modules, each of which comprises a substrate; a microstrip conductor formed on one surface side of the substrate; a ground plate formed on the other surface side of the substrate; and conductive pads which are disposed on both sides of a strip conductor portion which extends from said microstrip conductor via a tapered portion, and which are connected to the ground potential of said ground plate through a via hole, wherein the strip conductors of this plurality of millimeter wave modules are connected to each other using conductive ribbon. Moreover, when a plurality of millimeter wave modules is connected to form a millimeter wave system, the effect produced by the interaction between the unnecessary conductive pads connected to the ground potential and the strip conductor can be reduced.

Abstract: An apparatus for forming a quarter wave step between a waveguide of a radiating element under test and a waveguide associated with test equipment being used to test the radiating element. The apparatus includes a housing including a first bore, a second bore and a third bore, with the second bore forming a quarter wave step between the first and third bores. A pair of circuit boards each including a ring resonator are disposed at the transition areas between the first and second bores and the second and third bores. The ring resonators cancel the reactive component that would otherwise be introduced into the propagating wave as it travels through the quarter wave step portion of the apparatus. The apparatus is relatively short in length and easily implemented in a test environment to test various microwave components.

Abstract: A printed circuit board is described. That printed circuit board includes a capacitive load that is coupled to a signal trace. The signal trace has a first section and a second section. The first section is positioned between the capacitive load and the second section. The second section has a first width, and the first section includes first and second lines that each have a width that is smaller than the first width.

Abstract: A printed board having a structure for equalizing propagation times on transmission lines connecting the same pair of circuit elements at several terminals. The structure controls each propagation delay by connecting each transmission line partially in different dielectric layers having different dielectric constants in a multi-layered printed board regardless of a distance between the terminals to be connected.

Abstract: A strip transmission line to waveguide transmission line transition or impedance coupling is described. A strip transmission line is separated from a ground plane by a dielectric therebetween, and an aperture is formed through the ground plane and the wall of a waveguide transmission line on the other side of the ground plane (ground plane and wall may be the same piece). Each transmission line is terminated reactively, or at a port; for simple coupling across the transition, one end of each transmission line forms a reactive stub termination, such as an open circuit end. A waveguide channel waveguide walls and a waveguide base connected therebetween may be provided. The walls of such waveguide are coupled with the ground plane to provide a waveguide top for the waveguide transmission line.

Abstract: A method of tuning transmission line impedance includes the step of determining a desired impedance for a transmission line. A capacitive stub is periodically added to the transmission line. A physical quantity to be removed from each of the capacitive stubs to achieve the desired impedance is identified. The identified physical quantity is then removed to establish the desired transmission line impedance. A method of forming an impedance bridge includes the step of affixing a set of capacitive stubs to a bridging transmission line that has a first end and a second end. The vertical height of the set of capacitive stubs is tapered from the first end to the second end to form an increasingly high impedance between the first end and the second end.

Abstract: A balun comprises a first conductive layer disposed on a top surface of a substrate, the first conductive layer having first and second end portions, a second conductive layer having a shorter length than the first conductive layer and disposed on the top surface of the substrate, the second conductive layer having first and second end portions, the first end portion of the second conductive layer serving as a balanced transmission line in cooperation with the first end portion of the first conductive layer, the substrate having a through hole electrically connected to the second end portion of the second conductive layer, and a third conductive layer disposed on a bottom surface of the substrate, the third conductive layer having a first end portion electrically connected to the second end portion of the second conductive layer via the through hole, and a second end portion that serves as an unbalanced transmission line in cooperation with the second end portion of the first conductive layer, and the third c

Abstract: A low cost millimeter wave (MMW) module for a microwave monolithic integrated circuit (MMIC) includes a carrier board formed of a dielectric material and having at least one MMIC die mounted thereon and at least one interface line, such as a 50 Ohm microstrip interface line. A base plate is formed of a material that has a higher unmatched coefficient of thermal expansion (CTE) than the carrier board and supports same. A housing is mounted over the carrier board and engages the base plate. The housing has at least one subminiature coaxial connector (SMA) interface mounted thereon. A flexible circuit interconnect, such as a fuzz button, connects the subminiature coaxial connector and MMIC die through the interface line. A thermal interface member is positioned between the carrier board and base plate to aid in heat transfer between the base plate and housing and the lower CTE carrier board.

Abstract: A waveguide-to-microstrip transition (30) for converting and directing electromagnetic wave signals to an electronic signal processing component (53). A waveguide (32) directs the signals to a waveguide input and is received by a probe (36). A bent microstrip line (40A) which is connected to the probe (36) directs the received signals from the probe (36) to the electronic signal processing component (53). An output port (43) provides a connection between the bent microstrip line (40A) and the electronic signal processing component (53). The output port (43) is not inline with respect to the probe (36), but the microstrip line (40A) includes a bend so as to direct the received signals from the probe (36) to the output port (43).

Abstract: There is provided a microstrip line—waveguide conversion structure, an integrated circuit package for high frequency signals provided with this conversion structure, and a manufacturing method therefor, which are capable of reducing the passage loss even when frequencies in the millimeter band are employed, which has a simple structure, and which is capable of application to broadband frequencies.

Abstract: A single-wire time-domain reflectometer (TDR) combines the best performance features of prior art “electronic dipsticks” in a high accuracy implementation that allows tank penetration though a small opening. A wire-horn structure is employed to launch TDR pulses onto a single wire transmission line, wherein the horn wires can be flexed inwards so the dipstick structure can be inserted through a small tank opening. Once inside the tank, the horn wires flex to their normal state to provide a controlled reference reflection while simultaneously providing high coupling efficiency to the dipstick. The TDR system determines the fill-level of a tank by measuring the time difference between a reflection created at the wire-horn, which all is at the top of a tank, and a reflection from a material in the tank. The TDR employs automatic time-of-peak (TOP) detectors and incorporates a 2-diode sampler, a low-aberration pulse generator, and a 0.001% accurate timebase.

Abstract: RF feedthroughs for use with monolithic microwave integrated circuits (MMIC) are installed in environmentally protective or hermetically sealed packages that provide electromagnetic shielding. A feedthrough for an MMIC package has a dielectric substrate, a microstrip or transmission line formed on the substrate for transmitting high frequency electronic signals and a wall disposed above the transmission line and the substrate. The wall of the feedthrough has a varying thickness so that the narrowest portion of the wall is disposed on the transmission line substantially perpendicular to the substrate. The transmission line also has a varying width so that the narrowest width portion of the transmission line crosses the narrowest portion of the wall. The narrowest portion of the wall may be created by placing two oppositely facing concaved surfaces on each side of the wall. To reduce parasitic capacitance, the substrate and the wall may each have an air cavity embedded in respective bodies.

Abstract: A circuit package for a microwave signal comprises a substrate defining a MMIC surface of the substrate and an opposing non-MMIC surface of the substrate. The substrate is devoid of signal carrying vias. A waveguide is disposed on the MMIC surface of the substrate. A MMIC is disposed on the MMIC surface of the substrate, and the MMIC is in electrical communication with the waveguide. An I/O port is in electrical communication with the waveguide wherein a transmission path for the signal is provided from the I/O port, through the waveguide and to the MMIC. In an alternative exemplary embodiment of the invention, the I/O port of the circuit package is electrically connectable to a PC board. The MMIC surface of the substrate faces the PC board when the I/O port is electrically connected to the PC board.

Abstract: A multilayer ceramic device (100) includes a plurality of dielectric layers (104A-G) separated by ground planes (114) and includes a plurality transmission line segments (118) in generally folded configuration for defining a tapered transmission line (102). The profile of the transmission line may vary and includes such profiles as embodied in the depicted lines (200, 206, 212).

Abstract: A better impedance match between a signal transmitting component and a signal transmitting component circuit in a semiconductor circuit is achieved by controlling the parameters of the conducting path coupling the signal transmitting and receiving components. The parameters are controlled such that the portion of the conducting path coupled to the transmitting component has a characteristic impedance generally matching the output impedance of the transmitting component and the portion of the conducting path coupled to the signal receiving component has a characteristic impedance generally matching the input impedance of the signal receiving component. The impedance in portions of the conducting path can controlled by varying the geometric cross-section of the conducting path, the composition of the portion of the conducting path, and/or the amount or nature of the doping of the portion of the conducting path.

Abstract: A printed circuit board is described. That printed circuit board includes a capacitive load that is coupled to a signal trace. The signal trace has a first section and a second section. The first section is positioned between the capacitive load and the second section. The second section has a first width, and the first section includes first and second lines that each have a width that is smaller than the first width.

Abstract: A signal transmission unit includes a first transmission line, a second transmission line, and a tapered transmission line coupling the first transmission line to the second transmission line. The tapered transmission line has a width and a length and the width changes along the length according to one or more functions. The one or more functions include but are not limited to linear functions, non-linear functions, hyperbolic functions, and exponential functions.

Abstract: The invention relates to a microwave module having an outer face with a connection device. In the module the connection device presents, on the outer face, a central conductive zone and a peripheral conductive zone, and inside the volume of the module, connective zone, and inside the volume of the module, connection to the device takes place by means of coplanar conductors comprising a central signal conductor connected to the central conductive zone, and lateral ground conductors connected to the peripheral conductive zone. The connection is favorable to miniaturization and is suitable for operating over a broad band.

Abstract: A transition from a planar transmission line to a waveguide has a planar transmission line patterned onto a glass substrate. A mode transformer 1 on the substrate 3 is electrically connected to a transmission line 2 and converts a transverse electric or quasi-transverse electric mode signal carried by the transmission line to a waveguide mode signal. A combination of a first extension of the substrate 3 and a dielectric portion having some depth makes up a first impedance matching element 13. A second impedance matching element 14 is a combination of a second extension of the substrate 3 and a dielectric portion having another depth greater than the first depth. The aperture created by the second impedance matching element launches an RF signal into the air for use as a wireless communication signal. Also disclosed is a method for optimizing a transition according to the teachings of the present invention for alternative dimensions and dielectrics.

Abstract: A dielectric line converter which includes a dielectric stripline; an upper conductor surface and a lower conductor surface sandwiching the dielectric stripline; the upper and lower conductor surfaces having a first spacing in a first region along the dielectric stripline so as to form a first-kind dielectric line, a second spacing which is substantially zero in a second region so as to form a second-kind dielectric line, and a third spacing which is less than the first spacing in a line conversion region between the first and second regions. Grooves may be formed in the opposing surfaces of the upper and lower conductor surfaces, and the dielectric stripline may be arranged in the grooves. Impedance matching between the first-kind and second-kind dielectric lines is arranged n the line conversion region. The length of the line conversion portion may be set to be an odd multiple of &lgr;/4.

Abstract: A tunable phase shifter includes a waveguide, a finline substrate positioned within the waveguide, a tunable dielectric layer positioned on the finline substrate, a first conductor positioned on the tunable dielectric layer, and a second conductor positioned on the tunable dielectric layer, with the first and second conductors being separated to form a gap. By controlling a voltage applied to the tunable dielectric material, the phase of a signal passing through the waveguide can be controlled.

Abstract: An arrangement is disclosed for connecting two identical electromagnetic wave guides with rectangular cross-section, which serve to transmit linearly polarised electromagnetic waves and the rectangular hollow spaces of which are twisted with respect to one another in such a way that their corresponding axes run at right angles to one another. Between the two wave guides a connecting element is arranged, by means of which a low-reflection rotation of the polarisation plane of the waves to be transmitted takes place from the polarisation plane of one wave guide into the polarisation plane of the other wave guide orthogonal thereto.

Abstract: The present invention provides a system board and an impedance control method thereof. The board includes a plurality of modules or devices, and a control apparatus for controlling the modules or devices. Signal lines are connected from the control apparatus to the plurality of modules or devices and are arranged so that the length of the signal lines between the control apparatus and the plurality of modules or devices becomes shorter the distance from the control apparatus increases. Therefore, the present invention can reduce the signal distortion phenomenon by controlling the characteristic impedance of the signal lines between the control apparatus and the plurality of modules or devices such that the characteristic impedance decreases exponentially with increasing distance from the control apparatus in the case in which modules or devices are plugged into the system board.

Abstract: There is provided a microstrip line-waveguide conversion structure, an integrated circuit package for high frequency signals provided with this conversion structure, and a manufacturing method therefor, which are capable of reducing the passage loss even when frequencies in the millimeter band are employed, which has a simple structure, and which is capable of application to broadband frequencies. This package is provided with a base member 4 on which an MMIC 2 and the like are installed, a dielectric substrate 5 which is provided on this base member 4, a microstrip line 6 which is provided on the dielectric substrate 5 and which is electrically connected to the integrated circuit for high frequency signals, a frame member 7, in which an opening 7a which encloses the integrated circuit for high frequency signals is formed, and in which a concave portion 7b which engages with the dielectric substrate 5 is formed, and a cover member 8 which seals the opening 7a of frame member 7 and creates an airtight seal.

Abstract: A planar waveguide-to-microstrip adapter, a waveguide antenna and a downconverter all formed on a single dielectric substrate. The waveguide-to-stripline adapter is connected to the waveguide antenna and includes a tapered section attached to a microstrip line. The tapered section, which may be linear or may follow some other more complex taper function such as a Chebyshev function, adapts a signal propagating within the waveguide antenna to the microstrip line or vice versa.

Abstract: In order for it to be possible to manufacture a transition with a cost-effective stamping or diecasting or cold-molding process or with a plastic injection-molding process with subsequent metal plating, at least one ridge situated in the waveguide, which reduces the waveguide cross section in the direction of the stripline, has a cross section which tapers conically in the direction of the stripline.

Abstract: An umbrella-shaped matching network (10, 14, 16) for matching phase and impedance in a power amplifier (2). The matching network (10, 14, 16) employs rounded corners (22). The rounded corners (22) reduce microwave signal scattering losses, because they are less prone to signal radiation than square corner power combining networks. The matching network (10, 14, 16) includes slits (24) defining separated arms (26). The slits (24) are positioned in such a way that they provide phase and amplitude balance for the signal presented to the amplifiers (2). The slits (24) also prevent current from traveling transversely.

Abstract: A waveguide filter is provided having a plurality of asymmetrical corrugated resonators. The filter may also include an input section and an output section including a low-pass filter unit and a transformer unit. The low-pass filter unit includes a plurality of symmetrically corrugated slots, and the transformer unit includes at least one stepped transformer section for matching the filter to an external waveguide line. Each of the asymmetrically corrugated resonators may include a pair of opposed slots of different depth, a long slot and a short slot. The resonators provide at least one reflection zero and two transmission zeros to the frequency response of the filter, thus providing high-pass, band-pass and low-pass filter properties in a single filter structure.

Abstract: A corrugated waveguide filter has a plurality of coupled resonator cavities arranged in a horizontal or vertical manner. The filter may include an input transformer section and an output transformer section for matching the filter to external waveguide lines. Each resonator includes at least two extracted slots (or cavities) that are grouped in close proximity to each other, and which may be symmetrically or asymmetrically implemented in the waveguide. The resonators each contribute one reflection zero and two transmission zeros to the frequency response of the filter, the reflection zero being located within the pass-band of the filter, and the two transmission zeros located either at the high-side or low-side of the pass-band depending upon whether the resonator is a low-pass type or a high-pass type. The dimensions of each resonator, including the depth of the slots and the distance between the slots, determines the position of the reflection zero and whether the resonator is low-pass or high-pass.

Abstract: In a millimeter wave module or the like having both a normal NRD guide and a hyper NRD guide, a conversion portion structure for non, radiative dielectric waveguides of different types has excellent conversion characteristics at the connection between the two types of NRD guides. In a first conversion portion, the width of a dielectric strip is changed from the width of a dielectric strip in the hyper NRD guide portion to the width of a dielectric strip in the normal NRD guide portion, grooves of approximately the same depth as grooves in the hyper NRD guide are provided extending as far as the second conversion portion, and in a third conversion portion, the width of these grooves widens perpendicular to the propagation direction of electromagnetic waves and parallel to the face of conductive plates. According to this structure, guide conversion can be achieved with low radiation in a predetermined frequency band.

Abstract: A circuit board having a transition region at its perimeter. The transition region provides a deliberate increase in impedance between the voltage and ground plane from the interior side of the transition region where the board impedance is approximately that of the board impedance at an interior region of the circuit board to the edge side of the transition region where the impedance level approximates or is slightly less than that of surrounding air. In one example, the voltage plane in the transition region has a geometric configuration that provides a decrease in plane material (such as a hole, stripe, or triangle pattern) from the interior side to the edge side of the transition region. With other examples, the distance between the voltage and ground plane increases from the interior side to the edge side of the transition region.

Abstract: A normal NRD guide is constituted in the part to be coupled with a dielectric resonator, a hyper NRD guide for simply transmitting the LSM01 mode is constituted in a multipoints circulator part, the normal NRD guide is constituted in a coupler part, the hyper NRD guide is constituted in the mixer part, and the normal NRD guides are constituted in a dielectric line switch part and in a connection unit between components.

Abstract: A phase shifter including a phase-shifting slab having a phase-shifting member is used in conjunction with a quasi-TEM transmission line having at least one active line and one ground. In some embodiments, the phase-shifting slab is inserted between the active line and the ground. The phase-shifting member is advantageously configured so that as it is advanced between the active line and the ground plane, a varying amount of dielectric material passes therebetween. Varying the amount of dielectric material between the active line and the ground changes the effective dielectric constant of the transmission line. Such a change in the effective dielectric constant causes a change in the propagation velocity of a signal traveling through the transmission line. In that manner, a phase shift is introduced in the signal relative to other signals.

Abstract: A transition is provided for interfacing a coplanar waveguide with a three dimensional microwave waveguide. The transition includes three coplanar conductors that are formed integrally with and extend from the coplanar waveguide. The transition extends into the microwave waveguide through a slot, with the plane of the transition being perpendicular to the direction of propagation of the electric field in the waveguide. The center conductor of the transition is a patch whose width increases. The other two conductors are attached to the side conductors of the coplanar waveguide and to the exterior of the waveguide. They flank the patch and have curved edges complementary to those of the patch. The gaps are initially narrow, and become wider gradually. Further, as each guide steers the electric field while changing direction by 90.degree., it rotates the orientation of the electric field vector by the same amount.

Abstract: The invention relates to a transition between a ridge waveguide and a planar circuit on which a conductor is provided. The transition includes at least one conductive link connecting the end of said ridge to said conductor between two contact points. According to the invention, the contact points face a common access provided for putting the conductive link in place. It is thus possible to implement the contact points industrially, e.g. by means of a thermocompression machine.

Abstract: A waveguide for microwave radar level gages that includes a process sealed barrier in the waveguide that is impedance matched with bore transition sections of the waveguide at opposite ends thereof. The impedance matching results in positioning of the tapered end of the barrier offset from the ends of the bore transition sections.

Abstract: A slotted line tuner, also capable of operation as a fully automated tuner, to provide arbitrary termination in high frequency waveguide media for use with frequencies of interest between 1 and 1000 GHz is disclosed. The electrical tuner is adapted to match the impedance of two waveguide media, or enhance or modify the characteristic impedance of a media relative to that of another one. The tuner utilizes a non-conductive rectangular bar vane made out of low loss, low dielectric constant material as the probe, with special gold plated areas, that is inserted through the slot of the line into a reduced height waveguide. The position and depth of this gradual probe penetration creates a continuously variable tuning of the complex impedance, ranging from a very low reflection state up to high reflection states together with an unlimited capability of phase change in its reflection.

Abstract: A process sealed waveguide is formed in a flange mounted on a tank, and is used for transmitting microwave energy from a source of microwave energy to an aperture of an antenna on the interior of the tank. The process sealed waveguide includes a mechanical barrier to prevent escape of fluid under pressure or liquid from the interior of the tank, and also serves to reduce impedance mismatch between the air, vapor, or liquid filled waveguide or antenna apertures. The flange is mated to the microwave source through an electronic housing to flange adapter that interfaces with the flange in a manner to provide a vent in case the mechanical barrier fails so pressure is released, and to provide flame quenching if flames are present. The adapter includes a second waveguide having a process sealed mechanical barrier mounted coaxially with the mechanical barrier in the waveguide in the flange.