Huawei RRU3908 base station circuit analysis (part 2 of 2)

The Huawei RRU3908 is an outdoor Radio Base Station with one to four carriers and one to six sectors at 20/40 Watt RF output power per carrier.

Central Processing Units

Network communication is handled by a Freescale MPC8321 PowerQUICC2 CPU which runs at 200 MHz and has 2x 256 MB Hynix DDR2 RAM. It utilises a PMC QuadPHY 10 GB controller for the two optical input / output.

Decoding and encoding of the single bit streams for ADC and DAC are handled by the 3 Altera Cyclone III FPGA and the custom Huawei SD6151RBI controllers.

The single bit streams are treated by the Texas Instrument TMS320 series DSP CPUs. TMS320C6410 which is a fixed-point DSP that only calculates with integer numbers and the TMS320CT16482 1 GHz DSP CPU calculates floating point numbers.

Receive part

The input signal comes in two out of phase lines and are first treated by a Skyworks SKY73021-11 1.7 to 2.2 GHz downconversion mixer to get the frequency from 2.2 GHz to 550 MHz.

The local oscillator for the downconversion mixer is a Analog Devices ADF4110B.

A SIPAT SAW filter is used for isolation.

Depending on signal origin or type, I assume that the Analog Devices AD8376 Variable Gain Amplifiers are used before the signal lines split out into either a 3G ADC line or 4G ADC line.

The 3G line analog to digital conversion is handled by the Analog Devices AD6655-10 which is a 14-bit 150 MSPS chip that is specifically targeted for the 3G base stations.

The 4G line has a few more components as there is 2 MCL HSWA+1110 SPDT RF switch that feeds into 2 Maxim MAX2039E up/dowoconversion mixer and through a additional MCL HSWA+1110 SPDT RF switch it is handled by the Analog Devices AD9230-11-200 ADC which is a 11-bit 200 MSPS chip.

All timing is handled by the Analog devices AD9516-3 which is a 14-output clock generator with a built in 2 GHz local oscillator.

Transmit part

The single bit datastream from the Altera Cyclone III FPGA is handled by 2 Analog Devices TxDAC AD9788 which are specified for 16-bit 800 MSPS.

To get the signal up in frequency to the broadcast carrier frequency 2 Analog Devices ADL5375-05 upconversion modulators are used. These has a range from 400 MHz to 6 GHz.

The signal is then sent through a 5 staged ceramic resonator band pass filter.

Signal phase can be switched from the setup of transistors and EMC Technology & Florida RF Labs HPJ2F hybrid couplers.

The pre-amplifier before the signal is sent to the power amplifier is a Freescale MMG3004NT1 high linearity amplifier capable of 17 dB amplification in the range of 400 MHz to 2.2 GHz.

To control the signal strength a MCL 31R5 digital step attenuator sits before the output connector. This is a 31.5 dB attenuator that can work in 0.5 dB steps from a 6-bit serial control interface.

Power Amplifier

The power amplifier uses two stages where the first is a Infineon PTMA180402FL 40 Watt RF LDMOS that through a Xinger II XC1900A-03S hybrid coupler feeds two 90 degree out of phase signals to the output stage transistors which are NXP BLF6G20LS-140 140 Watt RF LDMOS.

The output is recombined in a Xinger II XC1900A-03S hybrid coupler before leaving to the diplexer through a circulator.

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Huawei RRU3908 base station teardown (part 1 of 2)

The Huawei RRU3908 is an outdoor Radio Base Station with one to four carriers and one to six sectors at 20/40 Watt RF output power per carrier.

Part 1 is the teardown itself with a walkthrough of different design highlights.

Part 2 is coming online in the following 1-2 weeks.

Part 2 is a complete circuit analysis and will also have high res pictures uploaded to this article.

For some different RF technology and techniques explained, here are some highlights from my previous videos.

Up/Downconversion explained: https://youtu.be/qO127zY3voE?t=865
SAW filters explained: https://youtu.be/qO127zY3voE?t=963
Ceramic bandpass filter explained: https://youtu.be/h9-KhfQM3nI?t=729

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Ericsson RBS 2216 Auxiliary Power Units teardown

I have updated a old teardown post with a new video about the auxiliary power units.

Read the old post and see all the details, pictures and amplifier teardown here: http://kaizerpowerelectronics.dk/teardown/ericsson-rbs-2216-900-mhz-base-station-teardown/

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Moving to a new lab (Part 3&4) Work shop tours

Here you get a short glimpse of the new space for the work shop.

This is part 3 and 4 in a series of videos on moving out, moving in and setting up the new lab / work shop.

I am moving out of the apartment and into our own house, which has a room dedicated to the laboratory and a work shop for rough work.

Part 3

Part 4

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Teardown of a Merlin Gerin Pulsar ESV 22+ UPS

Here is a new teardown of a small 2.2 kW UPS that provided backup power for a small radio system used by a taxi company.

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Moving to a new lab (Part 2) New basement lab and workshop tour

Here you get a short glimpse of the new space for lab and work shop.

This is part 2 in a series of videos on moving out, moving in and setting up the new lab / work shop.

I am moving out of the apartment and into our own house, which has a room dedicated to the laboratory and a work shop for rough work.

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Moving to a new lab (Part 1) Old basement lab tour and future projects

Follow me as I move from my old small 10 sq.m. lab to a new 20 sq.m lab and with additional 20 sq.m work shop.

This is part 1 in a series of videos on moving out, moving in and setting up the new lab / work shop.

I am moving out of the apartment and into our own house, which has a room dedicated to the laboratory and a work shop for rough work.

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Taxi Radio Basestation teardown – UHF/VHF Storno radio

This is a teardown of a complete Taxi computer and radio base station system. The Taxi car computer and connection box is used for location tracking, taxation, passenger detection and correct price calculation. All done in order to make sure that correct taxes are paid to the government but also to ensure that fair prices are billed to the customers.

The radio base station backbone of the systems are rather old and works in the 150 MHz range for both transmitting and receiving.

The two amplifiers are a Storno CQF612 and a Storno CQF9112, there is plenty of historic data to find on these using google if it is of further interest to the reader.

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Computer scrap gold money WITHOUT chemicals or mechanical processing, part 2

Part 2 is now ready that I have received all confirmations, papers and the money is in my bank account :)

It only took 5 days from I sent off the package till I had the money, awesome and fast service!

If you missed part 1, see it here: http://kaizerpowerelectronics.dk/technology/computer-scrap-gold-money-without-chemicals-or-mechanical-processing/

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How to build a Tesla coil. Design, theory and compromises!

A live broadcast that I did on Sunday, February 4, 2018 with focus on designing Tesla coils with special focus on the DRSSTC topology.

Questions about the Tesla coil theory and design tools can be asked during the broadcast and I will answer them to my best knowledge 🙂

DRSSTC design guide: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/

MMC calculator: http://kaizerpowerelectronics.dk/calculators/mmc-calculator/
Helical coil calculator: http://kaizerpowerelectronics.dk/calculators/helical-coil-calculator/
Spiral coil calculator: http://kaizerpowerelectronics.dk/calculators/spiral-coil-calculator/
Gate drive calculator: http://kaizerpowerelectronics.dk/calculators/igbt-gate-drive-calculator/
Snubber capacitor calculator: http://kaizerpowerelectronics.dk/calculators/snubber-capacitor-calculator/

Helical, spiral and topload calculators: http://deepfriedneon.com/tesla_frame0.html

SSTC theory: http://www.richieburnett.co.uk/tesla.shtml

JavaTC, best Tesla coil calculator around: http://www.classictesla.com/java/javatc/javatc.html

GDT design: http://thedatastream.4hv.org/gdt_index.htm
GDT troubleshooting: http://www.richieburnett.co.uk/temp/gdt/gdt2.html

Steve Ward Universal Driver 1.3: http://www.stevehv.4hv.org/new_driver.html
Steve Ward Universal Driver 2.1b: http://stevehv.4hv.org/leadcomp/UD2_1revB/

Inspiration:
Steve Ward: http://www.stevehv.4hv.org/SSTCindex.htm
Loneoceans: http://loneoceans.com/labs/
Mads Barnkob: http://kaizerpowerelectronics.dk/tesla-coils/

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