CN105577219A - A Broadband Transceiver Applied to Wired Coaxial Ethernet - Google Patents

Abstract

The invention provides a broadband transceiver used for wired coaxial Ethernet. The broadband transceiver comprises a receiving passage, a transmitting passage, and an internal clock module. The receiving passage comprises a low noise amplifier, a lower frequency conversion mixer, a filter, and an output buffering unit. The transmitting passage comprises an intermediate frequency amplifier, an upper frequency conversion mixer, and a power amplifier. The internal clock is generated by a phase-locked loop PLL, and the clock signals can be provided to the upper frequency conversion mixer and the lower frequency conversion mixer to realize the upward-shifting and the downward-shifting of the frequency spectrum. The broadband transceiver used for the wired coaxial Ethernet is advantageous in that by adopting the ultra-broadband radio frequency and intermediate frequency integrated circuit design technology, all of the ECO commercial frequency ranges and the signal bandwidths can be covered, and then the great adaptability and the wide market prospect can be provided.

Description

A Broadband Transceiver Applied to Wired Coaxial Ethernet

technical field

The invention relates to the field of radio frequency integrated circuits, in particular to a broadband transceiver applied to wired coaxial Ethernet.

Background technique

Since 2008, with the acceleration of the introduction of policies and norms related to the integration of telecommunications networks, radio and television networks and the Internet, the national government has continuously strengthened its support. The radio and television departments in various places have also accelerated the transformation of the two-way network. The EPON+ active EOC solution based on HomePlugAV technology is currently the most suitable solution for the existing radio and television coaxial cable network. Various network equipment manufacturers have also launched their own EOC products. Due to the gap in technical level, the quality and performance of EOC products of various network equipment manufacturers are also very different.

EOC (Ethernet over Cable) technology is a technology that transmits Ethernet baseband data through a coaxial cable. As an optical node device for two-way network transformation, the EOC local end device is connected to the EPONONU optical network of the metropolitan access network, and the EOC terminal of the downlink home user to realize the conversion and modulation of the Ethernet signal from the EPONONU main control part. After the EOC low-frequency signal is coupled with the cable TV signal, it is sent out from the output terminal to realize the connection application with the terminal equipment.

EOC can be divided into modulation (active) EOC and baseband (passive) EOC according to different transmission frequencies. Active EOC can be divided into low-frequency mode and high-frequency mode according to the modulation signal frequency band. Currently, low-frequency technologies include HomePNA, HomePlug, etc.; high-frequency technologies include BIOC, HiNOC, WiFi, MoCA, etc. Since various technical solutions have their own advantages and disadvantages, and the radio and television networks in various regions are in a state of independent operation and lack of unified management, there is a large gap between the two-way transformation plans and promotion efforts in different regions. This results in a more diverse demand for EOC chips. The current commercial chips are often only for specific standards, the frequency band is narrow, and the processing bandwidth is limited, which does not meet the status quo of complicated domestic standards and adjustable bandwidth.

Due to the popularity of cable television and the high transmission rate of coaxial cables, EOC technology has a relatively broad market prospect. At the same time, with the development of services such as high-definition TV and radio and television broadband Internet access, EOC equipment needs to provide higher bandwidth to support the expansion of subsequent services of radio and television operators. Therefore, how to obtain an EOC chip covering all current EOC commercial frequency bands and signal bandwidths, so that the EOC chip has great adaptability and broad market prospects has become an urgent problem to be solved by those skilled in the art.

Contents of the invention

In view of the above-mentioned shortcoming of prior art, the object of the present invention is to provide a kind of wideband transceiver that is applied to wired coaxial Ethernet, is used for solving the narrow frequency band of EOC chip in the prior art, the bandwidth of processing is limited, not It meets the problems of complicated domestic standards and adjustable bandwidth.

In order to achieve the above purpose and other related purposes, the present invention provides a broadband transceiver applied to wired coaxial Ethernet, the broadband transceiver at least includes:

Receive path, transmit path and internal clock module;

The receive path includes a first amplifier, a first mixer, a first filter, and an output buffer;

The first amplifier receives a radio frequency input signal and is used to amplify the radio frequency input signal;

The first mixer is connected to the first amplifier, and is used for mixing the output signal of the first amplifier and the local oscillator signal generated by the internal clock circuit, and moving the radio frequency signal to an intermediate frequency;

The first filter is connected to the first mixer, and is used to filter the output signal of the first mixer;

The output buffer is connected to the first filter for driving a load;

The transmission path includes a second amplifier, a second mixer and a third amplifier;

The second amplifier receives an intermediate frequency input signal and is used to adjust the amplitude of the intermediate frequency input signal;

The second mixer is connected to the second amplifier, and is used to mix the output signal of the second amplifier with the local oscillator signal generated by the internal clock circuit, and move the intermediate frequency signal to the radio frequency;

The third amplifier is connected to the second mixer for amplifying the output signal of the second mixer and outputting a radio frequency output signal.

Preferably, the internal clock module is a phase-locked loop circuit.

Preferably, the gain of the first amplifier is adjustable.

Preferably, the first amplifier is a low noise amplifier.

Preferably, the first filter is a passive or active structure.

Preferably, the bandwidth of the first filter is adjustable.

Preferably, the output buffer is an intermediate frequency variable gain amplifier.

Preferably, the second amplifier is a variable gain amplifier.

Preferably, the third amplifier is a power amplifier.

Preferably, it also includes an external second filter connected between the first amplifier and the first mixer.

Preferably, a bandgap reference circuit providing a reference voltage and a reference current is also included.

Preferably, a serial peripheral interface for data transmission is also included.

As mentioned above, the broadband transceiver applied to wired coaxial Ethernet of the present invention has the following beneficial effects:

The broadband transceiver applied to the wired coaxial Ethernet of the present invention can process radio frequency signal frequencies covering 800M-2.7GHz, is compatible with 50M-200MHz intermediate frequency signal bandwidth, and is compatible with the mainstream EOC technical protocol in the current market. The broadband transceiver applied to the wired coaxial Ethernet of the present invention covers all current EOC commercial frequency bands and signal bandwidths by adopting ultra-wideband radio frequency and intermediate frequency integrated circuit design technology, and has great adaptability and broad market prospects.

Description of drawings

FIG. 1 is a schematic diagram of a broadband transceiver applied to wired coaxial Ethernet according to the present invention.

Component designation description

1 Broadband Transceiver for Wired Coaxial Ethernet

111 Low Noise Amplifier

112 first mixer

113 first filter

114 output buffers

115 second filter

121 variable gain amplifier

122 second mixer

123 power amplifier

13 PLL circuit

14 bandgap reference circuit

15 serial peripheral interface

RF_in RF input signal

IF_out intermediate frequency output signal

IF_in IF input signal

RF_out RF output signal

detailed description

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

See Figure 1. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

As shown in Figure 1, the present invention provides a broadband transceiver 1 applied to wired coaxial Ethernet, the broadband transceiver 1 at least includes:

Receive path, transmit path and internal clock module;

The receiving path includes a first amplifier, a first mixer 112, a first filter 113 and an output buffer 114;

The first amplifier receives a radio frequency input signal RF_in for amplifying the radio frequency input signal RF_in;

The first mixer 112 is connected to the first amplifier, and is used for mixing the output signal of the first amplifier with the local oscillator signal generated by the internal clock circuit, and moving the radio frequency signal to an intermediate frequency;

The first filter 113 is connected to the first mixer 112 for filtering the output signal of the first mixer 112;

The output buffer 114 is connected to the first filter 113 for outputting an intermediate frequency output signal IF_out to drive a load;

The transmission path includes a second amplifier, a second mixer 122 and a third amplifier;

The second amplifier receives an intermediate frequency input signal and is used to adjust the amplitude of the intermediate frequency input signal;

The second mixer 122 is connected to the second amplifier, and is used for mixing the output signal of the second amplifier with the local oscillator signal generated by the internal clock circuit, and moving the intermediate frequency signal to the radio frequency;

The third amplifier is connected to the second mixer 122 for amplifying the signal output by the second mixer 122 and outputting a radio frequency output signal RF_out.

As shown in FIG. 1 , the broadband transceiver 1 includes a receiving path, a transmitting path and an internal clock module.

The receiving path is used to process the radio frequency signal received by the antenna to obtain an intermediate frequency signal and send it to the baseband module to ensure that the subsequent baseband module can recognize the input signal.

The transmission path is used to process the baseband signal to be sent by the baseband module to obtain a radio frequency signal, so as to ensure that the transmitted signal can be transmitted over a long distance.

The internal clock module is used to generate internal clock signals and provide clock signals required by each module. The most important thing is to provide local oscillator signals for the receiving path and the transmitting path, so that the radio frequency signal in the receiving path can be changed is an intermediate frequency signal, and the intermediate frequency signal in the transmission path becomes a radio frequency signal. As shown in FIG. 1 , in this embodiment, the internal clock module is preferably a phase-locked loop circuit 13 . A phase-locked loop circuit 13 (PhaseLockedLoop, PLL) can provide accurate and stable local oscillator signals for the broadband transceiver, for signal modulation and demodulation, signal frequency modulation and demodulation, and can ensure modulation and demodulation and frequency modulation And the demodulated signal more accurately reflects the original signal, improving the ability of anti-interference.

As shown in FIG. 1 , the receiving path includes a first amplifier, a first mixer 112 , a first filter 113 and an output buffer 114 .

The first amplifier is connected to the radio frequency input signal RF_in received by the antenna, and is used for amplifying the radio frequency input signal RF_in, while suppressing the noise of the subsequent module, so as to improve the overall sensitivity of the receiving channel. As shown in FIG. 1 , in this embodiment, the first amplifier is preferably a low noise amplifier 111 (Low Noise Amplifier, LNA), and the gain of the low noise amplifier 111 can be adjusted. The low noise amplifier 111 is used to amplify weak signals, which can effectively reduce the noise of the amplifier itself and improve the signal-to-noise ratio of the output signal.

The receiving path can also include an external second filter 115. As shown in FIG. In this embodiment, the second filter 115 is a surface acoustic wave filter (SurfaceAcousticWaveFilter, SAWFilter), and the surface acoustic wave filter has the advantages of small size, suitable for miniature packaging, good consistency, and no need for adjustment.

If the receiving path includes the external second filter 115, then the first mixer 112 is connected to the second filter 115; if the receiving path does not include the external second filter 115; filter 115 , the first mixer 112 is connected to the low noise amplifier 111 . As shown in Figure 1, in this embodiment, the first mixer 112 is connected to the second filter 115, receives the output signal of the second filter 115, and is connected to the phase-locked loop at the same time Circuit 13, the first mixer 112 is a down-conversion mixer (DownMixer), and the radio frequency signal output by the second filter 115 is mixed with the local oscillator signal provided by the phase-locked loop circuit 13, The first mixer 112 moves the radio frequency signal to an intermediate frequency for processing by a subsequent baseband module.

As shown in Figure 1, the first filter 113 is connected to the first mixer 112, and filters the intermediate frequency signal output by the first mixer 112 to filter out harmonics and interference outside the signal bandwidth signal, preventing aliasing and interference. The first filter 113 can be a passive or active structure, and the bandwidth of the first filter 113 can be adjusted. In this embodiment, the first filter 113 is an active filter with adjustable bandwidth.

As shown in Figure 1, the output buffer 114 is connected to the first filter 113, in this embodiment, the output buffer 114 is a variable gain amplifier (VariableGainAmplifier, VGA), used to drive low impedance load, the gain of the output buffer 114 is fixed or adjustable, and in this embodiment, the output buffer 114 is a variable gain amplifier with adjustable gain. The output buffer 114 outputs the IF output signal IF_out to subsequent baseband modules.

The transmit path includes a second amplifier, a second mixer 122 and a third amplifier.

The second amplifier receives the IF input signal IF_in. As shown in FIG. 1 , the second amplifier is a variable gain amplifier 121 for adjusting the amplitude of the IF input signal IF_in.

As shown in Figure 1, in this embodiment, the first mixer 112 is connected to the second amplifier, receives the output signal of the second amplifier, and is connected to the phase-locked loop circuit 13 at the same time, so The first mixer 112 is an up-conversion mixer (UpMixer), which mixes the intermediate frequency signal output by the second amplifier with the local oscillator signal provided by the phase-locked loop circuit 13, and the second mixer The device 122 moves the intermediate frequency signal to the radio frequency, so that the frequency of the transmitted signal can reach the frequency of propagation in the atmosphere.

As shown in FIG. 1, the third amplifier is connected to the second mixer 122, and is used to amplify the output signal of the second mixer 122 and output a radio frequency output signal RF_out, and the radio frequency output signal RF_out The magnitude of is large enough that it will not be attenuated beyond recognition due to long-distance transmission.

As shown in FIG. 1 , the broadband transceiver further includes a bandgap reference circuit 14, which provides reference voltage and reference current for internal circuits to ensure stable operation of the internal circuits.

As shown in FIG. 1 , the broadband transceiver 1 further includes a serial peripheral interface 15 (Serial Peripheral Interface, SPI), and the serial peripheral interface 15 is used to realize data transmission. The serial peripheral device interface 15 is a high-speed, full-duplex, synchronous communication bus, and only takes four lines on the pins of the chip, which saves the pins of the chip and provides a convenient way for the layout of the PCB. Save space and provide convenience.

The working principle of the broadband transceiver 1 applied to wired coaxial Ethernet is as follows:

Receive data:

The low noise amplifier 111 receives the radio frequency input signal RF_in from cables, antennas or other devices that receive radio frequency signals in the atmosphere, and the radio frequency input signal RF_in is attenuated after long-distance propagation, and the low noise amplifier 111 is adjusted The gain amplifies the radio frequency input signal RF_in to a state that the subsequent modules can identify and process, and at the same time, the low noise amplifier 111 suppresses the noise of the subsequent modules, so as to improve the overall sensitivity of the receiving channel. In this embodiment, an external second filter 115 is connected after the low noise amplifier 111, and the second filter 115 is used to filter the output signal of the low noise amplifier 111, Filter out interference signals outside the radio frequency spectrum and improve the signal-to-noise ratio. The first mixer 112 is the most important module in the receiving path, and the first mixer 112 moves the radio frequency signal filtered by the second filter 115 to the intermediate frequency band, so that the frequency of the input data in the operating frequency band of subsequent modules. The output signal of the first mixer 112 is filtered by the first filter 113 again. The bandwidth of the first filter 113 is adjustable, and can be adjusted according to the bandwidth of the intermediate frequency signal output by the first mixer 112. Adjusts to filter out harmonics and interfering signals outside the IF signal bandwidth, preventing aliasing and interference. The output signal of the first filter 113 is output to the output buffer 114. In this embodiment, the output buffer 114 is a special form of an intermediate frequency variable gain amplifier. For the first filter The output signal of 113 is amplified to output an intermediate frequency output signal IF_out to drive a low impedance load. The intermediate frequency output signal IF_out is presented as intuitively perceivable audio or video information after subsequent identification and processing.

send data:

The variable gain amplifier 121 amplifies the IF input signal IF_in, and adjusts the amplitude of the IF input signal IF_in, so as to ensure that the transmitted signal can still be identified after being attenuated by long-distance transmission. The second mixer 122 is the most important module in the transmission path. The second mixer 122 moves the intermediate frequency signal amplified by the variable gain amplifier 121 to the radio frequency band, so that the frequency of the transmitted data works In the transmitting frequency band, it is convenient for cable transmission. The power amplifier 123 amplifies the radio frequency signal output by the second mixer 122 to obtain a radio frequency output signal RF_out to drive a low impedance load, and the low impedance load includes a cable or an antenna.

The broadband transceiver applied to the wired coaxial Ethernet of the present invention can process radio frequency signal frequencies covering 800M-2.7GHz, is compatible with 50M-200MHz intermediate frequency signal bandwidth, and is compatible with the mainstream EOC technical protocol in the current market. The broadband transceiver applied to the wired coaxial Ethernet of the present invention covers all current EOC commercial frequency bands and signal bandwidths by adopting ultra-wideband radio frequency and intermediate frequency integrated circuit design technology, and has great adaptability and broad market prospects.

In summary, the present invention provides a broadband transceiver applied to wired coaxial Ethernet, including a receiving path, a transmitting path and an internal clock module. The receiving path includes a low-noise amplifier (LNA), a down-converting mixer, a filter, and an output buffer unit; the transmitting path includes an intermediate frequency amplifier, an up-converting mixer, and a power amplifier; the internal clock is generated by a phase-locked loop PLL. The clock signal is provided to the up-converting and down-converting mixers to move up and down the frequency spectrum; the low-noise amplifier in the receiving path is used to amplify the input signal while suppressing the noise of the subsequent module to improve the overall sensitivity of the receiving path; The gain of the low-noise amplifier can be adjusted; an external filter can be inserted between the low-noise amplifier and the down-conversion mixer to filter out interference signals outside the radio frequency spectrum; the down-conversion mixer in the receiving path moves the radio frequency signal to Intermediate frequency for subsequent baseband module processing; the filter in the receiving path is used to filter out harmonics and interference signals outside the signal bandwidth to prevent aliasing and interference; the filter can be passive or active structure; the filter bandwidth can be adjusted ; The output buffer unit in the receive path is a special form of an intermediate frequency variable gain amplifier (VGA), the main purpose is to drive low impedance loads; the output buffer unit gain is fixed or adjustable; the variable gain in the transmit path The amplifier is used to adjust the amplitude of the input intermediate frequency baseband signal; the up-conversion mixer in the transmission path moves the baseband signal to the radio frequency for easy cable transmission; the power amplifier 123 in the transmission path amplifies the radio frequency signal and can drive low impedance load (cable or antenna). The invention adopts ultra-wideband radio frequency and intermediate frequency integrated circuit design technology, covers all current EOC commercial frequency bands and signal bandwidths, and has great adaptability and broad market prospects. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (12)

1. A broadband transceiver applied to wired coaxial Ethernet, characterized in that, the broadband transceiver at least includes: Receive path, transmit path and internal clock module; The receive path includes a first amplifier, a first mixer, a first filter, and an output buffer; The first amplifier receives a radio frequency input signal and is used to amplify the radio frequency input signal; The first mixer is connected to the first amplifier, and is used for mixing the output signal of the first amplifier and the local oscillator signal generated by the internal clock circuit, and moving the radio frequency signal to an intermediate frequency; The first filter is connected to the first mixer, and is used to filter the output signal of the first mixer; The output buffer is connected to the first filter for outputting an intermediate frequency output signal to drive a load; the transmission path includes a second amplifier, a second mixer and a third amplifier; The second amplifier receives an intermediate frequency input signal and is used to adjust the amplitude of the intermediate frequency input signal; The second mixer is connected to the second amplifier, and is used to mix the output signal of the second amplifier with the local oscillator signal generated by the internal clock circuit, and move the intermediate frequency signal to the radio frequency; The third amplifier is connected to the second mixer for amplifying the output signal of the second mixer and outputting a radio frequency output signal. 2. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, characterized in that: the internal clock module is a phase-locked loop circuit. 3. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, characterized in that: the gain of the first amplifier is adjustable. 4. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, wherein the first amplifier is a low noise amplifier. 5. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, characterized in that: the first filter is a passive or active structure. 6. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, characterized in that: the bandwidth of the first filter is adjustable. 7. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, wherein the output buffer is an intermediate frequency variable gain amplifier. 8. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, wherein the second amplifier is a variable gain amplifier. 9. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, wherein the third amplifier is a power amplifier. 10. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, further comprising an external second filter connected between the first amplifier and the first mixer device. 11. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, further comprising a bandgap reference circuit for providing a reference voltage and a reference current. 12. The broadband transceiver applied to wired coaxial Ethernet according to claim 1, further comprising a serial peripheral device interface for realizing data transmission.