Home > Documentation > 2 way masthead amplifier circuit

2 way masthead amplifier circuit

Ref document number : Country of ref document : EP. Kind code of ref document : A1. Ref country code : DE. Country of ref document : US.


We are searching data for your request:

2 way masthead amplifier circuit

Schemes, reference books, datasheets:
Price lists, prices:
Discussions, articles, manuals:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.
Content:
WATCH RELATED VIDEO: How to Install a Masthead Amplifier and Power Unit

Vhf uhf power amplifier


Ref document number : Country of ref document : EP. Kind code of ref document : A1. Ref country code : DE. Country of ref document : US. An amplifier unit to be placed in an antenna mast and being pursuant to a radio system, which uses time division duplex. It comprises a transmitting and receiving branch in parallel, and the transmitting branch is used as a bypass path for the LNA in the receiving branch.

The unit is set to the transmitting mode, receiving mode and bypass mode by means of pin diode switches D1-D4, D7-D A passive bypass mode comes automatically into effect, if the unit loses its supply voltage.

At least one pin switch D7, D8, D9 is located transversely in the transmitting branch for switching it off, when the unit is set to the receiving mode. The structure comprises advantageously another, redundant, transmitting branch with series switches D10, D11, D12 , which is used for improving on the characteristics of the transmission path of the transmitting signals, when the biasing of the pin switches is possible.

The transmitting branches do not significantly degrade the received and amplified signal, because they are switched off when the unit is in the receiving mode, in which case the signals reflected from the lower end of the intermediate cable CBL can not propagate back to the input side of the LNA. The transmitting path and receiving path function, although the unit would loose its supply voltage. Masthead amplifier unit. The invention relates to an amplifier unit to be placed in an antenna mast, being in accordance with a radio system using time division duplex.

The amplifier unit is suitable for use especially in the base stations of cellular networks. In the two-way system, the transmitting and receiving can have a shared antenna, but processing signals propagating to opposite directions naturally requires their own transmission paths for both. On the receiving side, the first amplifier starting from the antenna should be as close to the antenna as possible, because the receive signal is low-level and a long intermediate cable would attenuate it even more and deteriorate the signal-to-interference ratio in the amplifier input.

For this reason the transmission path divides as viewed from the antenna in its vicinity to a transmitting and a receiving branch, and the latter includes a low-noise amplifier. When the antenna is close to the receiver and the transmitter, the transmission paths naturally continue separately to them. On the contrary, when the antenna is at the top of a mast relatively far away from the transmitter and the receiver, separate intermediate cables for transmitting and receiving would cause a considerable additional cost for the equipment.

For this reason, the transmission paths are usually joined again after the amplifier in the antenna mast so that an intermediate cable with only one shared transmission path for the transmitting and receiving comes down from the mast. The amplifier unit comprises a receiving branch and a transmitting branch in parallel.

The receiving branch comprises in the propagation direction of the signal a first receive filter , a low-noise amplifier or LNA and a second receive filter The receive filters are of band-pass type and they strongly attenuate frequency components outside the receive band thus cleaning the signal being received and protecting the LNA. The transmitting branch only comprises a transmit filter of band-pass type which strongly attenuates frequency components outside the transmit band thus preventing i.

The input of the first receive filter and the output of the transmit filter are coupled by a shared line to the antenna ANT. The output of the second receive filter and the input of the transmit filter are coupled to a T-bias circuit This is further coupled to the shared intermediate cable CBL, which is connected at its lower end to the other part of the base station equipment.

Via the T-bias circuit is received the supply voltage V 8 to the receiving branch, needed by it. In case of LNA damage, it can be provided with a bypass path. In Fig.

The bypass path requires two-way switches, by means of which it is enabled even as the LNA is disconnected from the transmission path. A masthead amplifier unit may comprise two parts like the one in Fig. In this case the receiving branch of one part can be used also as a bypass path of the receiving branch of the other part.

When the TDD technique Time Division Duplex is used in the radio path, the bites of the signals propagating to the opposite directions are transferred in the same frequency band at different times, in their own time slots.

In that case a masthead amplifier unit according to Fig. The prevention is implemented using an antenna switch, by means of which the transmitter and the receiver are connected to the antenna in turn, or using a circulator, which passes the signal coming from the transmitter only to the antenna and the signal coming from the antenna only to the receiver. As an example about the latter way is the front stage in Fig. It comprises, starting from the antenna ANT, in order a directional coupler , a passband filter and a circulator The circulator has, in addition to an antenna port, a receiving port and a transmitting port.

To the receiving port connects the receiving branch, in which a switch and LNA are visible, and to the transmitting port connects the transmitting branch, in which an isolator and radio-frequency power amplifier are visible. A signal provided by the directional coupler informs about damages in the antenna, because it is proportional to the signal reflecting from the antenna. The filter cleans the spectrum of both the signal to be transmitted and the received signal.

The transmission line between the circulator and switch has the length of the quarter wave at the operating frequencies. The switch is a two-way switch, which is controlled by the signal TX ON, the state of which depends on whether a transmitting period is going on or not. In the transmitting period the switch shorts the transmission line between the circulator and switch, in which case the imped- ance of the line measured at the circulator is high.

In the receiving period the switch naturally connects the circulator to the LNA through said transmission line. The signal TX to be transmitted, coming from the power amplifier, is guided almost entirely towards the antenna in the circulator. The attenuation from the transmitting port to receiving port is e. In the receiving branch the high-impedance transmission line and switch attenuate more the signal propagating there so that the level of the transmitting signal reaching the LNA is e.

This kind of considerable attenuation is needed because of the relatively high level of the transmitting signal. The receiving signal RX coming from the antenna is guided almost entirely towards the LNA in the circulator.

The circulator and isolator attenuate the receiving signal propagating to the power amplifier e. The front stage according to Fig. In respect of the transmitting branch, the combining with the receiving branch takes naturally place at the line going to the circulator, because the power amplifier is located down -?

When the combining is implemented, new problems regarding transmission technology have to be solved, especially when also an arranging of the bypass path for LNA in the receiving branch is demanded.

The object of the invention is to implement a masthead amplifier unit using TDD technique, which comprises a bypass path for the low-noise amplifier and fulfils the technical requirements regarding the transmission. The amplifier unit according to the invention is characterised by what is presented in the independent claim 1. Some advantageous embodiments of the invention are described in the other claims. The basic idea of the invention is the following: In a TDD masthead amplifier unit, which comprises a transmitting and receiving branch in parallel, there is used the transmitting branch as a bypass path for the LNA in the receiving branch.

The unit is set to the transmitting mode, normal receiving mode and bypass mode by means of pin diode switches. A passive bypass mode comes automatically into ef- feet, if the unit loses its supply voltage. At least one pin switch is located transversely in the transmitting branch for switching it off, when the unit is set to the receiving mode. The structure comprises advantageously another, redundant, transmitting branch with series switches, which is used for improving on the characteristics of the transmission path of the transmitting signals, when the biasing of the pin switches is possible.

An advantage of the invention is that there is, in case the LNA gain disappears, a bypass path for the receiving signal in a masthead amplifier unit, which functions in accordance with the TDD technique. Another advantage of the invention is that the transmitting branch in parallel with the receiving branch of the unit does not significantly degrade the received and amplified signal. This is because the transmitting branch of the unit is switched off when it is in the receiving mode, in which case the signals reflected from the lower end of the intermediate cable can not propagate back to the input side of the LNA.

A further advantage of the invention is that the transmitting path and receiving path function, although the unit would loose its supply voltage. A further advantage of the invention is that an unit according to it can easily be provided with a redundant branch with good power handling capability and low generated intermodulation.

This is based on the forward biasing of the series diodes in the branch in question. The invention will now be described in detail. The description refers to the accompanying drawings in which. The amplifier unit is presented as a simplified principled drawing, and it serves as an introduction to the structures according to the invention proper. The unit comprises a first circulator on the side of the antenna ANT and a second cir- culator on the side of the intermediate cable CBL leading to a base station.

The first circulator has, in addition to an antenna port, a transmitting and receiving port, and the second circulator has, in addition to a base station port, a transmitting and receiving port.

Between the receiving port of the first circulator and the receiving port of the second circulator there is the receiving branch of the unit, which comprises a first switch , the LNA and the second switch in series. Between the transmitting port of the second circulator and the transmitting port of the first circulator there is the transmitting branch of the unit, which consists of a transmission line and a directional coupler , through which the transmission line travels.

The directional coupler provides a measuring signal proportional to the signal propagating towards the antenna, which measuring signal is taken to the control unit When its level rises to a certain value, the control unit immediately outputs to the switches , of the receiving branch a control, which sets them to non-conductive state. This takes place in every transmitting time slot of the TDD system, when a transmitting signal begins to enter from the transmitter of the base station.

This way the amplifier unit is applied to the transmitting mode, wherein the LNA has been isolated from the other circuit so that only very much attenuated transmitting signal reaches the LNA. The amplifier unit is in the normal receiving mode, when both the first and second switch is in the conductive state. In this case the receiving signal coming from the antenna is guided in the first circulator through its receiving port to the LNA and further, as amplified, in the second circulator through its base station port to the intermediate cable CBL.

The gain may disappear either for the LNA damage or because the supply voltage of the whole amplifier unit vanishes. For the former case the LNA is equipped with a watching circuit, and the level of a fault signal provided by the watching circuit changes, if the gain disappears.

The fault signal is led to said control unit , which sets to the switches , of the receiving branch to non-conductive state also when the LNA is damaged. In this case, the amplifier unit is in the bypass mode, which is then an abnormal receiving mode. Comparing to the wavelength, the transmission line between the receiving port of the first circulator and the first switch is so short that a high impedance is "seen" in the receiving port, when the first switch is non-conductive.

In this case the receiving signal coming from the antenna does not waste energy to the receiving port and has such a phase at the transmitting port that it can propagate to the transmitting branch Correspondingly, in the second circulator the receiv- ing signal can propagate to the intermediate cable CBL, since the transmission line between the receiving port of the second circulator and the second switch is very short compared to the wavelength.

This way the transmitting branch functions also as the bypass path for the LNA, when the amplifier unit is in the bypass mode. In fact, in its bypass mode the whole amplifier unit only is a passive lengthening of the transmission line of the intermediate cable CBL. When there is another branch in parallel with the branch including an amplifier, an active loop is constituted.

This is in principle a risk factor because of the risk of an oscillation. In order that no oscillation handicap would arise, the loop gain should be clearly less than one, for example dB. When the structure according to Fig. This means degradation of the receive signal quality, because the signal gone around down in the base station is naturally substantially delayed on the way.

It would help if a pin diode type switch is added in series to the transmitting branch, which switch would be set conductive in the transmitting mode and non-conductive in the receiving mode.


Amplifiers & Distribution

Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Corinne Richard. Dante Mencacci.

SLx 2 Way TV Amplifier With a masthead amplifier, the aerial signal is boosted before the coaxial cable losses, resulting in big improvements in.

Choosing the Best TV Signal Booster


The lowest-priced, brand-new, unused, unopened, undamaged item in its original packaging where packaging is applicable. Packaging should be the same as what is found in a retail store, unless the item is handmade or was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag. See details for additional description. Very easy to install, easy to set up, sturdy and works well. Verified purchase: Yes Condition: New. Skip to main content. About this product. Brand new: Lowest price The lowest-priced, brand-new, unused, unopened, undamaged item in its original packaging where packaging is applicable.

Masthead Amplifier Wiring Diagram

2 way masthead amplifier circuit

All ports DC powered. Bristol Communications and Electrical ltd accept returns on all items within 14 days. If there is no fault with the product, the buyer must pay the return postage costs, of which are non-refundable. This cost will be decided upon receipt of goods.

We are currently experiencing an increased volume of online orders, along with delays and general congestion within our freight and logistic networks.

PROception F Type Masthead Amplifier Power Supply 2 Way


Amplifiers will clear up any low-strength, fuzzy, or pixelated channels - in some cases, the number of channels you receive may change depending on your distance from the local broadcast towers. Crest Digital Signal Amplifier. All Crest antennas and accessories have been designed to meet the requirements of both the analogue and digital channels to give you the best sound and picture quality. Consider these similar alternatives as this Amplifiers will clear up any low-strength, fuzzy, or pixelated channels — in some cases, the number of channels you receive may change depending on your distance from the local broadcast towers. Ravaglioli lift price It is inserted into the antenna cable between the amplifier and the TV.

2 Way Masthead Amplifier, LTE, 15-30dB Variable Gain Kit

Masthead Amplifiers. Masthead amplifiers are designed to amplify the aerial signal before any loss occurs due to cable runs. Ideally they are installed on the same mast as the aerial, approximately 1 meter from the actual aerial. They can however be used further down the cable, in lofts etc. The masthead amplifier is powered remotely via the aerial cable by means of an inline plug in power supply unit, PSU.

Buy Ex-Pro 2 Way TV Aerial Masthead Amplifier Booster Kit with Variable Gain Control and Overload Protection for UHF/VHF TV Antenna Freeview HD at UK,Free.

Frequently Asked Questions

Something that is regularly used with the aerial and satellite sector but not commonly known outside the trade. It is not common knowledge that the same coaxial cable that feeds the TV or set top box can be used to power active devices. It can! The following guide will show you the uses of and how to install a masthead amplifier and power supply unit.

2 Way LTE Masthead Amp 15-30dB Variable Gain Kit - Aerial Amplifier & Splitter


The A-stage and B-stage Masthead Amplifier Wiring Diagrams that enter the key panel are related by way of a primary disconnect breaker, whilst the neutral Masthead Amplifier Wiring Diagram is linked to a terminal called the neutral bar or neutral bus. A floor bar also could be existing inside the primary service panel. The bottom bar is connected to the grounding rod or to the inspiration's steel supports. Inside of main support panels, the neutral bar and the bottom bar are linked jointly they work as a person.

Delivery Address Not set. Collection Address Not set.

Audio Signal Splitter Circuit. Its function is relatively simple: take a signal input, and create two outputs, one that is identical e. Description: The SP model is a high-performance signal splitter that converts one high-level DC voltage input into two proportional isolated mA control signals. Note there is no power required except to the 33k pullup resistor. The split signals are sent to multiple speaker units through its output sockets.

In electronics , an antenna amplifier also: aerial amplifier booster , Am antennefier is a device that amplifies an antenna signal , usually into an output with the same impedance as the input impedance. Typically 75 ohm for coaxial cable and ohm for twin-lead cable. An antenna amplifier boosts a radio signal considerably for devices that receive radio waves.




Comments: 1
Thanks! Your comment will appear after verification.
Add a comment

  1. Mezirr

    Brilliant phrase