RU2032980C1 - Frequency converter - Google Patents

Abstract

FIELD: radio broadcasting equipment. SUBSTANCE: frequency converter has input circuit 1, inductance coil 2 of heterodyne circuit, transistor 3, first and second capacitors 4,5, resistor 6, power supply source 7. First input 9 of converter to connect aerial is linked to first leads-out of input circuit 1 and first capacitor 4, second lead-out of first capacitor 4 is coupled to base of transistor 3 and to first lead-out of inductance coil 2 of heterodyne circuit which second lead-out is connected to collector of transistor 3 and to first leads-out of second capacitor 5 and resistor 6. Second lead-out of resistor 6 is coupled through power supply source 7 to second lead-out of second capacitor 5, emitter of transistor 3, second lead- out of input circuit 1 and second input 10 of converter to connect aerial. Inductance coil 2, first and second capacitors 4,5, form heterodyne circuit 8. EFFECT: simplified design, reduced power consumption. 1 dwg

Description

 The invention relates to the design and manufacture of broadcasting equipment, namely, devices for converting frequencies from one broadcasting ultrashort-wave (VHF) band to another.

 A device is known that converts the frequency of the VHF band, adopted in Russia, to the frequency of the VHF band of the West European standard (converter for VHF FM receiver), containing an input circuit, amplifier, local oscillator, balanced mixer. This device requires the use of power sources with a sufficiently high voltage, consumes significant power from the power source, and also has unsatisfactory weight and size characteristics.

 Of the known technical solutions, the closest device adopted for the prototype is a frequency converter (VHF converter) containing an input circuit connected to an antenna, an input amplifier, a local oscillator and a mixer made on transistors.

 This device converts the frequency of the VHF band, adopted in Russia, to the frequency of the VHF band, adopted in Western European countries, by summing the frequency of the input signal with the local oscillator frequency in the mixing stage.

 The disadvantages of the prototype include a sufficiently large power consumption, unsatisfactory mass and dimensional characteristics associated with a large number of different elements used in the converter circuit, as well as a significant level of intrinsic noise.

 The aim of the invention is to reduce power consumption and improve overall dimensions.

 To achieve the goal in a frequency converter containing an input circuit, a local oscillator inductor, a transistor, first and second capacitors, a resistor and a power source, the first input of the antenna connecting device is connected to the first terminals of the input circuit and the first capacitor, the second terminal of the first capacitor connected to the base of the transistor and the first terminal of the inductor of the local oscillator circuit, the second terminal of which is connected to the collector of the transistor and the first terminals of the second capacitor and resistor, the second output of the resistor through a power source is connected to the second output of the second capacitor, the emitter of the transistor, the second output of the input circuit and the second input of the device for connecting the antenna, while the inductor and the first and second capacitors form a heterodyne circuit.

 When conducting a search by sources of patent information and scientific and technical literature, the author did not find technical solutions containing the distinctive features of the proposed device, exhibiting similar properties, which allows us to conclude that the proposed device meets the criteria of the invention "significant differences".

 The drawing shows a diagram of the proposed device.

 The frequency converter contains: input circuit 1, inductor 2, transistor 3, first capacitor 4, second capacitor 5, resistor 6, power supply 7, heterodyne circuit 8, first 9 and second 10 inputs of the device for connecting the antenna.

 In this case, the first output of the input circuit 1 is connected to the first input 9 of the device for connecting the antenna and to the first output of the first capacitor 4, the second output of the first capacitor 4 is connected to the first output of the inductor 2 and the base of the transistor 3, the second output of the inductor 2 is connected to the first the terminals of the second capacitor 5 and resistor 6, the second terminal of the resistor 6 is connected through a power source 7 to the second terminal of the second capacitor 5, as well as to the emitter of the transistor 3, the second terminal of the input circuit 1 and the second input 10 of the device Properties for connecting the antenna, while the inductor 2, the first 4 and second 5 capacitors form a heterodyne circuit 8.

The device operates as follows. Frequency signals to be converted into the frequencies of the range available in imported VHF receivers come from the first 9 and second 10 inputs of the device for connecting the antenna to the output circuit, respectively, through the first capacitor 4 from the first input 9 for connecting the antenna to the base of transistor 3, and with the second input 10 for connecting the antenna to the emitter of the transistor 3. The transistor 3, the first capacitor 4, the inductor 2 of the local oscillator circuit 8 and the second capacitor 5 form a generator circuit (local oscillator) close to the capacitive three point. In this case, the conditions L1> L are satisfied, where L1 is the inductance of the inductor 2 of the heterodyne circuit 8, and L is the inductance of the inductor of the input circuit 1. Due to galvanic coupling, the collector base of the transistor 3 through the inductor 2 of the heterodyne circuit 8 transistor 3 is in the diode inclusion. The emitter diode of the transistor 3 periodically with a local oscillator frequency F _g determined by elements 2, 4, 5, switches from closed to open state. As a result of the received antenna, the signal F ₁ arriving at the inputs 9, 10 for connecting the antenna is bridged with a frequency of F _g , due to which combinational components with frequencies F _to mF ₁ ± nF appear in the nonlinear antenna circuit of the emitter junction _g , of which the RPU preselector selects the useful component of the total frequency Fc ₁ F ₁ + F _g , filtering out all the other signals. Resistor 6 limits the collector current to a value of the order of 0.3 mA. Specifically, the range 66-73 MHz is transferred to the frequency interval 92-99 MHz by adding a local oscillator signal with a frequency of 26 MHz.

Due to the extremely high sensitivity of the RPU in the VHF range (1-5 μV), the converter is required to have a voltage transfer coefficient of the order of unity, so the diode converter is functionally justified here because of its well-known advantages. Given the parametric effect of some regeneration of the input circuit on the side of the local oscillator circuit (L << L ₁ ), the transmission coefficient of the device is in the range of 0.7-1.5, which is quite acceptable.

≈69 МГц диапазон U -Гм; 88-108 МГц, выберем F

95 МГц, частота F_г F

F

26 МГц (при таком выборе частот наблюдается практически минимальное количество паразитных каналов приема).PRI me R implementation. Let's take specific data. VHF band of CMEA: 65.8-73 MHz, F

≈69 MHz band U-GM; 88-108 MHz, choose F

95 MHz, frequency F _g F

F

26 MHz (with this choice of frequencies, there is an almost minimal number of spurious reception channels).

≃ 70 МГц его нагруженная добротность
Q_н=

≃ 10 Индуктивность этого контура
L

≃ 0,15 МкГн где C_Σ С_м + С_бэ + С_ант + С суммарная емкость, емкость монтажа, емкость база-эмиттер, емкость антенны, емкость контура. Принимаем С_м 5 пф, С_бэ 10_пф, С_ант 6 пф, С 6,2 пф.Resonant Input LC Circuit Band
Δ F 73-66 7 MHz, its center frequency
F

≃ 70 MHz its loaded Q factor
Q _n =

≃ 10 Inductance of this circuit
L

≃ 0.15 MkHn where C _Σ С _m + С _бе + С _ant + C total capacity, mounting capacity, base-emitter capacity, antenna capacity, loop capacity. We accept C _m 5 pF, C _BE 10 _pF , C _ant 6 pF, C 6.2 pF.

+ C_КБ≃ 40 пф где С1 С2 75 пф, С_кб ≈3пф.The equivalent capacitance of the local oscillator circuit is taken equal to
C _equiv ≃

+ C _KB ≃ 40 pF where C1 C2 75 pF, C _KB ≈ 3 pF.

1 мкГн ≫ L что хорошо согласуется с введенным ранее ограничением.The calculated value of the inductance L1
L1

1 μH ≫ L, which is in good agreement with the previously introduced restriction.

≈ 3 кОм что совпадает с ранее приведенной оценкой из условия экономичности.Then the current at the operating point I 0.3 mA, U _BE 0.6 V when powered by one galvanic cell with U _n 1.5 V, the resistor is
R

≈ 3 kΩ, which coincides with the previously given estimate from the condition of economy.

0,225мА (учитываем разряд элемента со снижением тока вдвое)
t_раб=

≃ 9000 час т.е. один элемент обеспечивает продолжительность непрерывной работы преобразователя свыше года.The resource of continuous operation of one element A343 (capacity at small discharge currents A 2 A.h) with an average consumption of
current I _cp =

0.225mA (we take into account the discharge of the element with a decrease in current by half)
t _slave =

≃ 9000 hour i.e. one element ensures the duration of continuous operation of the converter over a year.

 The low supply voltage and low operating currents provide, together with the filtering effect of the parallel LC circuit, which is very frustrated by the relatively low frequency of the local oscillator, a low level of side signals of the device, not exceeding several millivolts in the range of 25-100 MHz. This radiation level is lower than that of typical VHF units having a local oscillator voltage of 4-6 V, despite the presence of UHF in the last stages, which reduce the leakage of signals into the antenna (the radiation power is proportional to the square of the voltage).

 1. The converter expands the functional and at the same time consumer capabilities of a wide class of foreign-made radio equipment, in fact "introducing" into it the VHF broadcast band with Mi-Fi quality. In addition, the device can be used as a remote repeater operating near the main RPU.

 2. The original circuitry solution provides the utmost simplicity, reliability, efficiency and complete autonomy of the converter during a year of continuous operation from one galvanic cell type A343 (A316).

 3. The converter is implemented in small dimensions, easy to use (just turn on the power and connect to the input of the main RPU), does not contain scarce elements.

 4. The converter has no industrial analogues in Russia and abroad.

 5. The industrial production of the converter will provide a significant economic effect. Due to the low cost with high consumer value, the product is able to provide a profitability of at least 500%

Claims (1)

 A FREQUENCY CONVERTER comprising an input circuit, a local oscillator inductor, a transistor, a first and second capacitor, a resistor and a power source, wherein the first output of the input circuit is connected to the first output of the first capacitor and is the first input for connecting the antenna, characterized in that, with In order to simplify and reduce power consumption, the second output of the first capacitor is connected to the base of the transistor and the first output of the local oscillator inductance coil, the second output of which is connected to the the transistor’s lecturer and the first terminals of the second capacitor and resistor, the second resistor terminal is connected through a power source to the second terminal of the second capacitor, the emitter of the transistor and the second terminal of the input circuit, which is the second input for connecting the antenna, while the inductor and the first and second capacitors form a heterodyne circuit.