Friday, May 13, 2011

Radiation Pattern of a Cell Tower Antenna

Radiation Pattern from the cell tower Antenna has been drawn for basic understanding of a radiation pattern.

This diagram was mainly used to describe why on a certain building the radiation levels vary from one apartment(say 7th floor) to the apartment above or below (6th and 8th floor) for a building at Khar (West), Mumbai.

The radiation pattern of a cell tower antenna is defined by its lobes. Radiation will be highest from the primary lobes in the horizontal direction. There is also radiation from secondary lobes.As seen in the figure, the readings that will be taken in between the lobes will be much lesser.

As seen in the figure, the radiation will also be high vertically downward from the secondary lobes. This is what most mobile operaters hide or are not aware of in India.


Distance is another critical factor. The power density varies by (1/R2), where R is the distance. People living within 50-300meter radius are in the high radiation zone. The figure below is a study from Germany. In the US, amplifiers of 1-2 Watt each are used in majority of the residential areas. However in India, at many places even 100 to 200 W amplifiers are used and there are clusters of antennas from multiple operators on the roof top of several residential and office premises.


Below is a simulated radiation pattern of a cell tower antenna by Prof. Girish Kumar from IIT Bombay, an expert on cell phone tower radiation and with experience of more than three decades in Antennas and Microwaves.


USHA KIRAN BUILDING - several cancer cases

Through the help of the above typical radiation pattern, let’s analyze the news reported in Mid-day, Mumbai dated Jan. 3, 2010, which stated - “Mumbai's swanky Usha Kiran building says the four cancer cases there could be linked to mobile towers installed on the facing Vijay Apartments”. The picture taken from the Usha Kiran building of the several antennas installed on the seventh floor of Vijay Apartments is shown in Fig. below.


Recently (as on Jan 2011) two more cancer cases have been reported on the 5th and on the 10th floor.
People living in the 6th, 7th and 8th floor in the opposite building will get maximum radiation as they are in the main beam direction. People living on the other floors will receive lesser radiation as beam maxima is reduced considerably as can be observed from vertical radiation pattern. In the horizontal direction again, people living in the front side of the antenna will receive much higher radiation compared to people living in the back side of antenna.

http://www.mid-day.com/news/2010/jan/030110-mobile-tower-cancer-cases-carmichael-road-posh-areas.htm

19 comments:

  1. Hi,

    This is very informative, however, I want to know more about radiation below cellphone towers, especially for the residents living in buildings who have erected cellphone towers on the terraces.

    ReplyDelete
  2. Dear Anand,
    As seen from the first figure, i.e, according to the radiation pattern of cell tower antenna, radiation also travels vertical downward. We have observed that the levels are generally high on the top 2-3 floors from roof top antennas. However, levels may vary based on the angle and construction material used.

    ReplyDelete
  3. Dear Neha,

    Thanks for the information. We are looking to buy a house where 6 antennas at 60 mt distance on a building opposite us. We are looking at a house on the 8th floor and its directly opposite our balcony at a distance of 60 mts.

    Is there anything that can be done to negate the radiation ? I read somewhere that there are different ways to do the same.

    Also, what can be done to remove the same legally ?

    ReplyDelete
    Replies
    1. Dear Rini,

      we can carry out Cell Tower Radiation Measurement Survey at your residence from health point of view followed by a report from Prof. Girish Kumar from IIT Bombay.

      Alternativley, you can check the levels using DETEX 189 - http://neha-wilcom.blogspot.in/2011/12/cell-tower-radiation-detector-detex-189.html which has been designed from health point of view and is simple and easy to use. Cost is Rs 4,950/-

      We have shielding solutions like Film, Curtain and Wall Paper. You can read details at: http://neha-wilcom.blogspot.in/2013/01/screen-saver-save-your-home-from.html

      Our contact details are given below. If you have any queries, please feel free to contact us.

      Regards,
      Neha Kumar

      Nesa Radiation Solutions Pvt. Ltd.
      2nd Floor, Plot No. 31,
      Sector 19C, Vashi
      Navi Mumbai 400 705
      Tel: (022) 41241800 / 9619378318
      Website - www.nesa.co.in
      Email - nesaglobal@gmail.com

      Delete
    2. You can go through the following presentation and documents for more information to create public awareness and convince operators to reduce the transmitted power.

      1) Report on Cell Tower Radiation by Prof. Girish Kumar sent to DOT with more than 200 references in the end - http://www.scribd.com/doc/44736879

      2) Presentation on Cell Tower Raidation Hazards by Prof. Girish Kumar, IIT Bombay - http://www.scribd.com/doc/132189401/Cell-Tower-Radiation-Report-by-Prof-Girish-Kumar-Dec-2012

      Regards,
      Neha Kumar
      nesaglobal@gmail.com / info@nesa.co.in

      Delete
  4. Hi,

    Thanks a lot for the information. I have one question. If my house is within 50m (assuming the dimensions in above diagram), then am I in the safe range?

    We have a tower in 14 m horizontal distance and about 10 m in height from the ground. I made the basic calculation and observed that our house does not fall in the 5-10 degree vertical range (as it is too close and our roof top barely touches the 10 degree line). This makes me think that our house is safe, am I correct? Please let me know.

    Thanks
    Satya

    ReplyDelete
  5. Hi Satya,

    '14 m horizontal distance and about 10 m in height from the ground' means your house is very close to the tower. Also, according to the guidelines, cell tower companies cannot install mobile towers at a height less than 36 meters from the ground.

    Also, according to the radiation pattern, maximum radiation in the horizontal plane is 120 degrees and in the vertical plane it is 6 degrees. However as several antennas are installed on one tower, each antenna will radiate in different directions and the area of coverage may vary.

    Since the antennas are only 14 meter away from your house, radiation levels can be very high even if your house is within the 10 degree line.

    I suggest you contact the TERM Cell (government body) to take readings in your house (however irrespective of the reading they always state that levels are safe at the end of the report) OR purchase a radiation monitor to check the radiation levels yourself. You can purchase this one from India: http://www.nesa.co.in/product-cell-tower-radiation-detector.html

    ReplyDelete
  6. hi,
    I m Satish Nalla staying in Soalpur(Maharashtra),The cell phone tower is installed on ground(open plot) just 4 meter next to my house.How radiation affects? plz reply,I m very worried.

    ReplyDelete
  7. hi,
    I m Satish Nalla staying in Soalpur(Maharashtra),The cell phone tower is installed on ground(open plot) just 4 meter next to my house.How radiation affects? plz reply,I m very worried.

    ReplyDelete
  8. Fantastic articles is post by you in this blog. You give a nice thing. Thank you for such a nice article. Every word of this blog helps me to give detail to me.
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    ReplyDelete
  9. hi,
    I m Shashidhar staying in Kundapur,The cell phone tower is installed on ground(GBT) just 4 meter next to my house. Tower height is 50 mtrs. How radiation affects? plz reply,I m very worried.

    ReplyDelete
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  11. There is absolutely NO scientific evidence that non-ionizing radiation of the type used in cellphones and wireless networks and even microwave communications can cause cancer, nor is there any known mechanism for it. If you know one, please publish and accept your Nobel prize in physics for showing that the photoelectric effect (Einstein), is incorrect.

    ReplyDelete
  12. Here are the facts: https://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/electromagnetic-fields-fact-sheet

    and

    This is an EXTREMELY large Danish study on cellphones:

    https://www.sciencedaily.com/releases/2011/10/111020191848.htm

    ReplyDelete
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  16. can cell towers be installed on 7 storey building with max height of 60 ft if no how to get them removed whom to complain

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