RU2749652C2 - Indoor television antenna - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to the field of radio engineering, namely to antennas for receiving an over-the-air television signal. The television antenna includes a housing inside which a hollow metal cone-shaped receiving element, an antenna amplifier and a unit for LED indication of the received signal level are placed, while the receiving element is located vertically in the housing and is mechanically and electrically connected with the top of the cone to the antenna amplifier board, and the cross-sectional diameter of the base of the receiving element is 1 / 2-1 / 4λ, where λ is the average operating wavelength of the television decimeter range, while the antenna amplifier includes an LC-bandpass filter, is made on one transistor with automatic signal gain control and with the possibility of receiving the output signal from the amplifier to the antenna output and to the unit of LED indication of the level of the received signal, the latter consisting of a signal level detector made on high-frequency sensitive semiconductors and a signal level indicator made on LEDs.

EFFECT: invention is aimed at amplifying the television signal.

3 cl, 2 dwg

Description

The invention relates to the field of radio engineering, namely, to antennas for receiving an over-the-air television signal.

An antenna is known that contains a flat supporting element, on both sides of which there are three dipole vibrators, consisting of two arms, the length of the longer side of the arm is 0.2 ... 0.3 * λ (λ is the average operating wavelength), powered from both sides of the supporting element by three directly connected quarter-wave two-wire transformers, connected in the center of the carrier on both sides, and thus forming two parallel contact pads for connecting the coaxial signal transmission line to the receiver. Moreover, each pair of arms of the dipole vibrators is located on both sides of the carrier, and the arms themselves diverge away from the supply points in such a way that each dipole vibrator occupies a sector of the carrier of 120 degrees (patent RU 186322, IPC H01Q 23/00, publ. January 16, 2019).

Known indoor antenna, the body of which is made in the form of a decorative soccer ball, having inside the structure: two receiving elements, made in the form of a spiral, located on the frame of the body, an antenna amplifier located at the base of the indoor antenna, and a coaxial cable through which the signal from the amplifier to the TV (CN 102790265 (A), IPC H01Q 1/12, H01Q 1/38, publ. 17.05.2011).

The disadvantages of known antennas are the low efficiency of receiving a television signal and the inconvenience of tuning the antenna due to the fact that these antennas do not have indicators of the received signal strength, and without a television receiver or set-top box it is not possible to determine whether the antenna is tuned for reception, it is installed in the zone of maximum television signal, or not.

The technical problem to be solved by the claimed technical solution is to increase the efficiency of receiving a television signal with the convenience of tuning the antenna.

The technical result is the amplification of the television signal. The problem is solved, and the technical result is achieved by a television antenna, which includes a housing of two hemispherical parts connected to each other to form a ball, inside which a hollow metal cone-shaped receiving element, an antenna amplifier and an LED indication of the received signal level are located, while the receiving element is located vertically in the housing and the top of the cone is mechanically and electrically connected to the antenna amplifier board, and the cross-sectional diameter of the base of the receiving element is 1 / 2-1 / 4 λ, where λ is the average operating wavelength of the television decimeter range, while the antenna amplifier includes an LC-band pass filter , is made on one transistor with automatic control of signal gain and with the possibility of receiving the output signal from the amplifier to the antenna output and to the LED indicator of the received signal level, the latter consisting of a signal level detector made at high frequencies sensitive semiconductors, and a signal level indicator made on LEDs.

According to the invention, in special cases:

- the antenna has seven LEDs on the unit of LED indication of the received signal level;

- all structural elements are located inside the plastic case.

The technical result is achieved as follows.

Due to its geometric shape, the receiving element (cone-shaped) makes it possible to equally receive a television signal from either side of the antenna (circular radiation pattern). The cross-sectional diameter of the base of the receiving element (cone) is calculated taking into account 1 / 2-1 / 4 λ of the received wavelengths (λ is the average operating wavelength of the television decimeter (UHF) range), this allows you to obtain a high coefficient of intrinsic gain of the receiving element. The vertically located receiving element (inverted cone) with its top is directly mechanically and electrically connected to the antenna amplifier board. This type of connection allows you to minimize electrical signal losses and reduce the level of leading noise, since additional detachable and non-detachable connections lead to insertion losses and induce additional noise in the receiving signal.

The receiving element concentrates the signal from several directions and transmits it through an LC-bandpass frequency filter (460-860 MHz), consisting of LC-chains (for example, on the site

http://m.knowledgr.com/00373954/%D0%9A%D1%80%D1%83%D0%B3%D0% BE% D0% BE% D0% B1% D0% BE% D1% 80% D0 % BE% D1% 82LC) to the antenna amplifier. Antenna amplifier is made on one transistor with low noise level (since one transistor is used) and with automatic control of signal gain. This single-transistor solution is much more efficient than multistage amplifier circuits, where, in addition to amplifying the amplitude of the useful signal, electrical noise appears and amplifies. Such noise leads to digital errors and negatively affects the quality of the digital television signal. The low noise single transistor solution maximizes the amplitude of the output signal. Feedback (OS), built on an RC chain (for example, at https://ru.wikipedia.org/wiki/RC-%D1%86%D0%B5%D0%BF%D1%8C, allows you to get a uniform output amplitude-frequency characteristic (AFC), that is, the gain does not change depending on the frequency of the input signal.In amplifiers with no feedback, with an increase in the signal frequency, a phase shift occurs between the input and output signal, as a result of which at some frequencies of the amplified signal self-excitation of the circuit occurs , that is, the amplifier turns into a generator, which is a disadvantage.

The block of LED indication of the received signal level determines the signal level at the amplifier output. The block of LED indication of the received signal level allows to visually determine the optimal location of the antenna by the number of LEDs that light up on it.

The essence of the invention is illustrated by drawings, where it is shown:

FIG. 1 - General view of an indoor television antenna in section;

FIG. 2 is a block diagram of the claimed indoor television antenna.

The figures indicate:

1 - upper part of the case

2 - the lower part of the body

3 - receiving element

4 - antenna amplifier

5 - block of LED indication of the received signal level

6 - housing base

7 - band pass filter

8 - transistor

9 - signal level detector

10 - signal level indicator on LEDs. The claimed antenna works as follows.

The antenna is connected to a television receiver or set-top box by a coaxial cable (not shown in the drawing), the cable has a power injector to separate the supply voltage and the high-frequency (HF) television signal.

From the receiving element (3) through a band-pass filter (7), which passes only television frequencies of 460-860 MHz, the signal enters the input of an amplifier made on a transistor (8). The gain feedback (OS), performed on the RC-circuit, allows you to obtain a uniform frequency response at the output of the transistor (8). The vertically located receiving element 3 (inverted cone) is mechanically and electrically connected with its top to the antenna amplifier board (4). This connection minimizes electrical signal loss and reduces the level of humming noise.

The unit of LED indication of the received signal level (5) consists of a signal level detector (9), made on high-frequency, sensitive semiconductors and an indicator (10), made on LEDs. The detector (9) determines the signal level at the output of the antenna amplifier (4) and at a low level, less than 60 dB / μV, only one LED lights up, signaling a signal failure. When moving the indoor television antenna to the zone of reliable reception, the detector (9) detects a high level, about 80 dB / μV, at the output of the antenna amplifier (4), while all the LEDs of the level indicator light up. In the presence of seven LEDs, the indication of the received signal level has the following four stages: no signal - one LED is on; low level - three LEDs are on, medium level - five LEDs are on and high level - all seven LEDs are on.

The block (5) of the LED indication of the received signal level makes it possible to visually determine the optimal installation location of the indoor television antenna by the number of LEDs that light up on it.

All structural elements are located inside the housing, which can be made of plastic.

Claims (3)

1. Television antenna, including a housing of two hemispherical parts connected to each other to form a ball, inside which there are a hollow metal cone-shaped receiving element, an antenna amplifier and an LED indicator of the received signal level, while the receiving element is located in the housing vertically and mechanically with the top of the cone and electrically connected to the antenna amplifier board, and the cross-sectional diameter of the base of the receiving element is 1 / 2-1 / 4λ, where λ is the average operating wavelength of the television decimeter range, while the antenna amplifier includes an LC-band pass filter, made on one transistor with automatic control of the signal gain and with the possibility of receiving the output signal from the amplifier to the antenna output and to the LED indicator of the received signal level, the latter consisting of a signal level detector made on high-frequency sensitive semiconductors and a level indicator i signal performed on LEDs. 2. Antenna according to claim 1, characterized in that it has seven LEDs on the unit for indicating the level of the received signal. 3. Antenna according to claim. 1, characterized in that all structural elements are located inside the plastic housing.

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