RU2657324C2 - Application of industrial watch stone as the millimeter range wave length semiconductor device housing and the oscillator with such device - Google Patents

Abstract

FIELD: radio engineering and communications.

SUBSTANCE: invention relates to radio engineering and can be used in the development and production of semiconductor devices for SHF electronic equipment in the millimeter wavelength range. SHF oscillator of the millimeter wavelength range contains an avalanche transit time diode located in the housing, which is made of bushing type industrial watch stone.

EFFECT: technical result of the invention is the creation of a housing for a SHF semiconductor element in the millimeter range, which provides an improvement in the parameters of this element by increasing its output power and reducing its own losses.

12 cl, 5 dwg

Description

The group of inventions relates to radio engineering and can be used in the design and manufacture of semiconductor devices for microwave electronics: generators, amplifiers, high-speed devices for controlling the amplitude and phase of electromagnetic waves in the millimeter wavelength range.

In order to increase the reliability of devices, microwave semiconductor devices are mounted in ceramic cases (RF Patent No. 2351037, publ. 03/27/2009).

The disadvantage of ceramic housings for microwave semiconductor devices in the millimeter range is that the resistance of the case losses is commensurate with the ohmic losses of the semiconductor structures of microwave devices (for example, an avalanche span diode has a negative resistance value of ~ 20 Ohms at a frequency of ~ 100 GHz), and also, that for mounting the ceramic body on the heat sink surface and closing the lid, in order to ensure tightness, soldering with molten solder is used, which inevitably introduces additional losses reduces the percentage yield of devices due to the geometry of these non-identical housings sizes.

In addition, the use in the millimeter range of metal-ceramic cases with high performance is limited by the capacity of the case, while in the short-wave part of the microwave range the dimensions of the known cases become comparable with the wavelength, as a result of which the case cannot be considered when developing and calculating the diode circuit as in parallel capacitance of a concentrated type. In this case, additional settings, pins, diaphragms, etc., must be introduced into the design of the semiconductor element, which inevitably leads to a decrease in the range of operation of the device, an increase in losses, and complexity of tuning to a given range.

Analysis of frequency characteristics in the short-wave part of the millimeter range: generators, amplifiers, modulators, etc. - the waveguide type showed that it is advisable to consider the diode body as a radial line located on a wide wall of the waveguide with dimensions that ensure the transformation of the input impedance of the electromagnetic energy transmission line to the terminals of the diode structure to realize parallel resonance (high-impedance state) conditions in the diode circuit. With given and controlled parameters of the diode structure and the inductance of its installation, broadband matching of the diode with the waveguide transmission line is achieved.

The technical result to which the invention is directed is the creation of a housing for a microwave semiconductor element in the millimeter range, which improves the parameters of this element by increasing its output power and reducing its own losses (reducing ohmic resistances in the circuit of a microwave semiconductor device).

The technical result is achieved when used as a case for a microwave semiconductor element in the millimeter range of a finished product for another purpose - an industrial watch stone such as a sleeve made of synthetic corundum - ruby - 10 (GOST 22029-76) and used in the watch industry as a support for the axis elements of the clockwork.

Another technical result that the invention is directed to is the creation of a millimeter-wave microwave oscillation generator using an avalanche-span diode, using a sleeve made of synthetic corundum - ruby - 10 as an industrial watch stone diode case.

The dielectric constant of ruby is 9. The approximate dielectric constant is 8.7 and 9, respectively, for alumina (Al ₂ O ₃ ) and aluminitride (AlN) ceramics used in the manufacture of cases for microwave elements in the millimeter range (http: // www.nevz-ceramics.com/en/produktyi-i-materialyi/podlozhki.html).

The dielectric loss tangent for ruby-10 is 0.0002, and for the indicated ceramics 0.0002 and 0.0003, respectively. The specific volume resistivity is 10 ¹⁴ for ruby-10 and 10 ¹⁴ , 10 ¹⁵ for ceramics, respectively. The design of a watch stone of the sleeve type is a flat cylinder with a through cylindrical hole (TU 25-1895-005-86), which is similar to the usual design of a ceramic case for a microwave semiconductor element in the millimeter range. The technology for their manufacture has been developed over a long period of use for the watch industry, which ensures high quality identical products.

The use of a ruby industrial sleeve as a case of a microwave semiconductor element in the millimeter range provides a reduction in the ohmic resistance in the contacts of the diodes and the mass assembly of diodes with a high percentage of output suitable for use in the microwave technology.

Reducing losses when using ruby industrial bushings is achieved by metallization of the ends of the bushings by spraying the contacts in vacuum on the end surfaces. This method eliminates the preliminary soldering of the ends of the housing due to the application of thermocompression welding of the housing to the base of the diode sleeve and closing the housing with a cover. Thus, the use of ruby industrial stones for assembling microwave semiconductor elements also makes it possible to organize the strength of group assembly of elements with an increased yield.

Another technical result in the form of creating a synchronized generator of microwave oscillations of the millimeter wavelength range on an avalanche-span diode (LPD), using an industrial watch stone as a sleeve type LPD case, is achieved in a device that is made on an LPD based on a regular section waveguide 0 , 8 × 1.6 mm, operating in the range of 110-180 GHz, and a coaxial line crossing the waveguide along a wide wall.

An LPD (1) is installed in the coaxial line, mounted in a ruby bush on a copper pin (Ø = 0.4 mm ~ λ / 4 and a height of 0.15 mm) and antiparasitic load (2). The design of the generator allows you to independently move during the tuning process the position of the antiparasitic load along the coaxial line relative to the waveguide channel. A sliding piston (3) is installed at one waveguide output of the structure, and the other is connected through a ferrite circulator to the load and a highly stable source of a synchronizing signal (synthesizer). In this case, the required magnitude and nature of the reactivity for the parallel resonance structure at the terminals of the semiconductor structure is achieved by changing the length of the radial line of the sleeve diameter. Also, the device provides the ability to adjust the transformation coefficient of the conductivity of the load n when changing the displacement of the axis of the coaxial line relative to the center of the waveguide.

≈ λ/2 относительно диода последовательно с импульсом диода подключается импеданс последовательного контура. В таких системах обеспечивается компенсация реактивных сопротивлений, улучшающая диапазонные характеристики генератора. Основным частотно-избирательным узлом СВЧ-цепи такого генератора является диод в металлодиэлектрическом корпусе с резонансной трансформацией импеданса к полупроводниковой структуре. Запасенная энергия в рассматриваемой СВЧ-системе сосредоточена в основном в области диода в корпусе, а обобщенная добротность системы оказывается минимальной.The possibility of changing the transformation coefficient n allows us to provide the required matching of the diode impedance and the load without the use of additional reactive inhomogeneities in the output section of the waveguide section of the GLPD. Changing the position of the reflective antiparasitic load changes the parameters of the generator. So with her position $$\mathcal{l}$$

≈ λ / 2 relative to the diode, the impedance of the series circuit is connected in series with the diode pulse. In such systems, compensation of reactance is provided, which improves the range characteristics of the generator. The main frequency-selective node of the microwave circuit of such a generator is a diode in a metal-dielectric housing with a resonant transformation of the impedance to a semiconductor structure. The stored energy in the microwave system under consideration is concentrated mainly in the diode region in the housing, and the generalized Q factor of the system is minimal.

Figure 1 shows the generator circuit on the LPD, where 1 is an avalanche-span diode in a ruby bush, 2 is an antiparasitic load, 3 is a sliding piston.

Figure 2 shows p ⁺ –p – n – n ⁺ - the structure of the LPD mounted inside the ruby sleeve, where 4 is the LPD, 5 is the ruby sleeve, 6 is the gilded copper pin, 7 is the top electrode with the cover, 8 is gold flattened .

Figure 3 shows a simplified equivalent circuit of a synchronized generator. The dotted line indicates the circuit for switching on the LPD. x ₁ ; x ₂ ; x ₃ - reactance, including the resistance of the inclusion of the Central rod and the resistance of the coaxial loop containing antiparasitic load; Z _p - short-circuit piston; Z _BP - the waveguide load of the radial line; r _p - loss resistance in the dielectric housing; r _with - loss resistance in the contacts of the installation of the housing elements; r _s is the spreading resistance; L _s is the inductance of the contact strips; x _d is the reactance of the diode structure; L _RL - wall thickness of the sleeve, which determines the equivalent length of the radial line; r _d is the negative resistance of the LPD.

Figure 4 shows the frequency dependences of the input conductivity of the radial line _{R p} (r) in the cross section r ₀ = d / 2, for different D / a (where a is the size of the wide waveguide wall): 1 - D / a = 0.31 ; 2 - D / a = 0.27; 3 - D / a = 0.23; 4 - D / a = 0.19; 5 - D / a = 0.58; 6 - D / a = 0.54; 7 - D / a = 0.5; 8 - D / a = 0.46; 9 - D / a = 0.42; 10 - D / a = 0.38; 11 - D / a = 0.39.

Figure 5 shows a diagram of the synchronized generator on the LPD, where 1 is the entrance to the ferrite circulator from the highly stable source of the synchronizing signal, 2 is the connection of the synchronized source on the LPD with the circulator, 3 is the microwave output to the load.

> 10. Очевидно, что полные потери в трансформаторе импульсов должны быть минимальны.An analysis of the impedance amplitude-frequency characteristics used by the LPD in the millimeter range with the optimal doping profile of p ⁺ - p - n - n ⁺ structures shows that, with the signal amplitudes corresponding to the maximum electron power and the optimal diameter of the p - n junction, the negative-resistance semiconductor modulus structure does not exceed 2-3 Ohm. In this regard, when an LPD is directly connected to a high-frequency circuit with a load equal to the wave impedance of the transmission line Wо, the transformation coefficient of the active component of the load impedance should be $$\frac{Wo}{\left|Z\right|d}$$

> 10. Obviously, the total loss in the pulse transformer should be minimal.

The main feature of creating high-frequency systems of generator-amplifier devices on LPD with minimal energy losses in the millimeter range is in ensuring high transformation coefficients of the impedance of the diode when it is included in the microwave circuit. In this case, the most appropriate is the creation of a transformer in close proximity to the semiconductor structure. The implementation of such a transformer with minimal intrinsic losses and the coefficient of transformation of impedances (K) into the high-frequency circuit of the device includes a transformed negative resistance of the diode, the module of which significantly exceeds the loss resistance in the transmission line.

When creating generators and amplifiers using LPD in the millimeter range, it is advisable to use metal-dielectric cases with distributed parameters as an impedance transformer.

In this case, it is advisable to consider the metal-dielectric casing as a radial line with distributed parameters, which ensures the transformation of the input impedance of the transmission lines to the diode structure inclusion terminals for realizing parallel resonance conditions in the device circuit.

The magnitude and nature of the impedance of the radial line driven to the terminals of the diode structure is determined by the expression:

,

,

where Ct (x, y) is the large radial cotangent;

where λ is the wavelength;

ε is the dielectric constant of the ruby sleeve;

r is the outer radius of the sleeve;

r ₀ is the inner radius of the sleeve;

h is the height of the sleeve.

It is seen that by changing the length of the radial line of the diameter of the sleeve, the required value and nature of the reactivity is achieved for the parallel resonance structure to be realized at the terminals of the semiconductor structure. Given the dimensions of the radial line, the frequency of parallel resonance is selected by the value of L _s (Fig. 3).

In practice, the value of L _s can be set by choosing the width of the contact plus (5) connecting the diode structure with the housing.

The LPD is made on a silicon p ⁺ - p - n - n ⁺ - type silicon semiconductor structure and a pn junction diameter of the chip of 20-30 μm with an optimal doping profile to achieve maximum energy parameters:

N _p = 4.0x10 ¹⁷ cm ^-3 ; L _p = 0.2 μm; N _n = 3.5x10 ¹⁷ cm ^-3 ; L _n = 0.2 μm.

An important feature of the developed design of the generator on the LPD is the ability to adjust the transformation coefficient of the conductivity of the load n when changing the displacement of the axis of the coaxial line relative to the center of the waveguide. The possibility of changing the transformation coefficient n allows us to provide the required matching of the diode impedance and the load without the use of additional reactive inhomogeneities in the output section of the waveguide section of the generator.

As a result, the main frequency-selective node of the microwave HFLD circuit is a packaged diode with a resonant transformation of the impedance to a semiconductor structure. The stored energy in such a microwave system is concentrated mainly in the region of the packaged diode, and the generalized Q factor of the system is minimal.

≈ λ/2 относительно диода последовательно с импульсом диода подключается импеданс последовательного контура. Известно, что в таких системах обеспечивается компенсация реактивных сопротивлений, улучшающая диапазонные характеристики генератора.Changing the position of the reflective antiparasitic load changes the parameters of the generator. So with her position $$\mathcal{l}$$

≈ λ / 2 relative to the diode, the impedance of the series circuit is connected in series with the diode pulse. It is known that in such systems compensation of reactance is provided, which improves the range characteristics of the generator.

Claims (12)

1. The use of industrial watch stone as a case for a microwave semiconductor element in the millimeter range. 2. The use according to claim 1, characterized in that the industrial watch stone is made in the form of a sleeve. 3. The use according to claim 1, characterized in that the industrial watch stone is made of synthetic corundum - ruby - 10. 4. The use according to claim 1, characterized in that at least one end of the sleeve is metallized. 5. The use according to claim 1, characterized in that the metallization of at least one end of the sleeve is made by spraying in vacuum. 6. Generator of microwave oscillations of the millimeter wavelength range, containing an avalanche-span diode located in the housing, antiparasitic load, characterized in that the housing is made of industrial watch stone type sleeve. 7. The generator according to claim 6, characterized in that the stone is made of synthetic corundum - ruby - 10 8. The generator according to claim 6, characterized in that it is made on the basis of a waveguide of regular cross section 0.8 × 1.6 mm, operating in the range of 110-180 GHz, and a coaxial line crossing the waveguide along a wide wall. 9. The generator of claim 8, characterized in that the avalanche-span diode is mounted on a copper pin in a coaxial line, which is made with the possibility of independent movement along the coaxial line of the antiparasitic load relative to the waveguide channel. 10. The generator according to claim 8, characterized in that one waveguide output of the structure is made with a sliding shorting piston, and the other is connected through a ferrite circulator with a load and a highly stable source of a synchronizing signal. 11. The generator of claim 8, characterized in that it is arranged to change the length of the radial line of the diameter of the sleeve. 12. The generator of claim 8, characterized in that it is configured to offset the axis of the coaxial line relative to the center of the waveguide.

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