FI64008B - ZONROER FOER PROJEKTILER - Google Patents

Description

! 64008

Proximity excitation for munitions Zonrör för projektiler

The invention relates to a proximity excitation for ammunition, comprising an active component such as an FET transistor or a bipolar transistor or other similar active member and a dielectric resonator adapted to act as an oscillator generator 5 using feedback.

Hitherto known Doppler stimuli operate at frequencies of about 50 MHz to 200 MHz. The frequency is caliber dependent, with long munitions representing the lower edge of the operating frequency limits and 10 short munitions representing the upper edge, respectively. This is because the length of the projectile, i.e., the part flying in the air, is about the order of a quarter of a wave to function as the second half of a half-wave dipole antenna.

The second half of the antenna structure is the inductance coil of the electronic oscillator circuit 15, which represents an electrically short, i.e. short, wavelength antenna.

The operation of the Doppler excitation is based on the fact that when the obstacle is approached, the transmitted wave is reflected back so that due to the mutual movement 20 it encounters the transmitter in the same phase with the new transmitted wave and sometimes in the opposite phase. It follows that the antenna is periodically loaded so-called. The Doppler frequency. This frequency is indicated by a suitably connected detector, for example a diode. The projectile can thus be detonated by a suitable electronic circuit when the desired level of the detector signal is exceeded.

Usually, the Doppler excitation has the same transmit and receive antenna. When it encounters a moving obstacle, part of the transmitted frequency is reflected back at a frequency changed by the Doppler frequency. The difference between these two frequencies, which is typically at low (audio) frequencies, is formed by the so-called a mixer element, which is typically a diode, such as a Schottky diode. Such a separation frequency is desired because it is easy to handle with conventional low frequency electronic circuits.

2 64008

With regard to the prior art, reference is made, for example, to U.S. Patent No. 3,833,905, which discloses a proximity excitation that uses bipolar transistors, coils, and capacitors to generate oscillation. The operating frequency of this known proximity stimulus is relatively low and the upper limit of the operating frequency is of the order of 300 MHz.

With regard to the state of the art, reference is further made to U.S. Patent No. 4,079,341, DOS Publication No. 3,007,580 and European Patent Application No. 0013174. These references deal with dielectric resonator feedback oscillators which are not self-oscillating mixers.

It is an object of the invention to provide an improvement over the currently known proximity stimuli. It is a more detailed object of the invention to provide a proximity excitation without the need for a separate antenna. It is a more detailed object of the invention to provide a proximity stimulus that operates at significantly higher frequencies. Yet another object of the invention is to provide a proximity stimulus with as few components as possible, as a result of which the proximity stimulus 20 becomes small in volume and light in weight.

The objects of the invention are achieved by a proximity exciter, which is mainly characterized in that the dielectric resonator is adapted to act as both a radiation transmitting antenna and a receiving antenna, whereby radiant energy is introduced and introduced into the proximity exciter via a dielectric resonator without an output conductor.

Other features of the proximity stimulus according to the invention are set out in claims 2-10.

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Numerous significant advantages are achieved with the proximity stimulus according to the invention. The scarcity of components makes the Doppler module according to the invention small in volume and light in weight, as a result of which it can be used in a wide variety of ammunition applications that require these properties. In the Doppler module according to the invention, only two components are required, i.e. an FET transistor or a bipolar transistor or other similar active element and a dielectric resonator. This makes it possible to reduce the manufacturing costs and increase the reliability of the Doppler module according to the invention and to reduce the price considerably.

The invention will be explained in detail with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figure 1 schematically shows an ammunition using a proximity stimulus according to the invention.

Figure 2 shows the operation of a Doppler radar as a block diagram.

Figure 3A shows one way in which the dielectric feedback required to generate oscillation can be provided.

Figure 3B shows another way in which the feedback performed by the dielectric button required to generate the oscillation 20 can be provided.

Figure 3C shows a third way in which the feedback provided by the dielectric button required to generate the oscillation can be provided.

Figures 4A and 4B show a schematic overview of a proximity stimulus according to the invention.

Figure 5 shows the electrical equivalent connection of the radar.

In Figure 1, the projectile is generally indicated by reference numeral 10. The projectile 10 comprises an electromagnetic wave-transmitting dome 11 containing a Doppler module 12 according to the invention. is marked in one plane of a beam of radiation generated by the Doppler module 12 according to the invention.

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In Figure 2, block 18 shows the transmission / reception as well as the mixing block and block 19 the logic circuit. In the self-oscillating mixer, vibration is generated as follows. A dielectric resonator 22 suitably coupled to the transistor circuit, as shown in Figures 3A-3C 5, causes a positive feedback between the drain and gate electrodes of the FET transistor 21, causing the transistor circuit to become unstable and begin to oscillate. The frequency of the oscillation depends on the dimensions of the dielectric resonator 22 and the environment in which it is located. It should be noted that the dielectric resonator 22 causes the te-10 to feedback only at its own resonant frequency.

This is also the frequency at which the dielectric resonator 22 radiates. The radiation is due to the fact that the resonator is an open structure in nature.

In Figures 3A-3C, a dielectric resonator 22 is connected by way of example between a drain and a gate electrode. However, the resonator 22 can also be placed in two other places, namely between the drain and source electrodes or between the gate and source electrodes.

20 In the connection methods (Figures 3A-3C), a negative voltage is applied to the deck and a positive voltage to the drain. These are introduced through filters 32 (Figure 5) which are not permeated by microwave power. This can be done, for example, with a standard microstrip low-pass filter or a choke 29 (Fig. 4A) wound from a very thin conductor wire, or a combination of these.

When the transmitted electromagnetic radiation of frequency f encounters a reflecting object, part of the transmitted power returns due to mutual motion at a frequency changed by a Doppler frequency equal to f ± f ^. The frequency f + means that the projectile 10 and the target move towards each other and the frequency f - fj, respectively, means that the projectile 10 and the target move away from each other.

The operating point of the FET transistor 21 is set so that the initial frequency f and the return frequency f t are mixed with each other, i.e. the active element, i.e. the FET transistor 21, forms the frequency difference, which is exactly the Doppler frequency f ^. The resulting Doppler frequency is amplified and passed through decision circuits to an igniter that performs ignition. In Fig. 2, the control signal from the logic circuit 19 is denoted by reference numeral 20.

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Although the cylindrical shape in the dielectric resonator 22 is the most conventional, parallelepiped or elliptical cylindrical dielectric resonators can also be used.

As shown in Fig. 4A, the output of the mixing result OUT / IF takes place by means of the drain resistor R, in this embodiment. By using d different transistor connections, the mixing result can be taken out of the second electrode, whereby the position of the resonator 22 can also change eo. by. Possible connection methods ova.t: 15 CE = common emitter connection CB * common base connection CC = common collector connection

Self-bias switching (the resistance between the gate and the high, which may be in connection with the transmission lines, in which case the high-frequency power passes through it, or it may be external, in which case the high-frequency power does not pass through it).

When using self-coupling (in CE), no external voltage is required at the gate electrode. Only the supply voltage must be.

Figure 4A shows a bias resistor 31 in connection with transmission lines.

The drain resistor R 1 (or the resistance of the other electrode, depending on the eo.) Can be a separate α 30 component, or it can be manufactured by thin-film or thick-film technology directly on the bias circuit, thus also improving the performance of the bias filter. Likewise, the source resistor R can be manufactured by thin or thick film technology or it can be a separate component.

The microstrip conductors 26 may be open, shorted, or terminated by a resistive load 27. The resistive load 27 can be made by 35 6 6 4 O C 8 discrete resistor or by thin or thick film technology directly as an extension of the conductors 26, as shown in Fig. 4A. Reference numeral 28 denotes a filter capacitor and reference numeral 29 denotes a choke.

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In Fig. 5, the FET transistor is denoted by reference numeral 21, the filter structure (choke, microwave filter, and capacitor) is denoted by reference numeral 32, the dielectric resonator equivalent components R *, L *, and C * are denoted by reference numerals 33, 34, and 35, the base end impedance Z and drain impedance by reference numeral 37. In the equivalent circuit, the transmission lines 26 are drawn in sections each having its own wave impedance and length (i = 1 ... 5). In practice, Z 1 is 50 Ω (i 1 ... 5) and (i = 1 ... 5) varies depending on the desired oscillation frequency, being, for example, 0-30 mm. Source resistor 15 is denoted by reference numeral 31.

The dielectric button 22, e.g. the height, diameter, and dielectric constant and thickness of the microstrip substrate.

The circuit starts to oscillate at the above-mentioned resonant frequency. In addition to providing vibration, the button 22 also acts as an antenna. Thus, it does not direct all the electromagnetic power from the drain to the gate, but according to Maxwell's equations, due to the open structure, the button 22 radiates part of the power at its above-mentioned resonant frequency.

When the radiation (frequency f) encounters a moving obstacle, part 30 is reflected back at a frequency f ± changed by the Doppler frequency and reaches the button. The button 22 thus also acts as a receiving antenna.

The new frequency now orbits the circuit when the return wave is received. This causes mixing. The transistor forms a frequency difference λ, which is a Doppler frequency and is obtained out of the circuit as a suitable filter which does not pass microwave power. The Doppler frequency in this application is typically a few kilohertz.

Claims (10)

A proximity excitation for ammunition comprising an active component, such as an FET transistor (21) or a bipolar transistor or other similar active member, and a dielectric resonator (22) adapted to act as an oscillator generator using feedback, characterized in that the dielectric resonator (22) is adapted to act as both a radiation transmitting antenna and a receiving antenna, whereby the radiant energy is applied and supplied to the proximity excitation via the dielectric resonator (22) without an output conductor. 10 Proximity excitation according to Claim 1, characterized in that the transmission lines (26) are microstrip lines. Proximity excitation according to Claim 1, characterized in that the transmission lines (26) are stripline lines. Proximity excitation according to Claim 1, 2 or 3, characterized in that the dielectric resonator (22) is made of a low-loss ceramic material. 20 Proximity excitation according to Claim 4, characterized in that the dielectric resonator (22) is barium nonatitanate Ba 2 T19 ° 20 ". Proximity excitation according to Claim 1, 2, 3, 4 or 5, characterized in that the dielectric resonator (22) is arranged between the drain (D) and the gate (G) of the FET transistor (21). Proximity excitation according to one of Claims 1 to 6, characterized in that the dielectric resonator (22) has a cylindrical shape. 7 640C8 Patent claims Proximity excitation according to one of Claims 1 to 7, characterized in that the output of the mixing result (OUT / IF) is effected by means of a drain resistor (R 1). 8 6 4 0 C 8 Proximity excitation according to one of Claims 1 to 8, characterized in that the frequency range of the proximity excitation is between 5 and 25 GHz. Proximity excitation according to Claim 9, characterized in that the frequency range of the proximity excitation is between 6 and 12 GHz. 9 6 4 C C 8