Heatsinks as quasi-antennas and frog forming: frequency and feeding point effect

HELHEL S., KARAMAN A. B., KOCAKUŞAK A.

JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, cilt.35, sa.16, ss.2153-2162, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 35 Sayı: 16
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1080/09205071.2021.1934572
  • Dergi Adı: JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Compendex, INSPEC, zbMATH, DIALNET
  • Sayfa Sayıları: ss.2153-2162
  • Anahtar Kelimeler: Radiation pattern of heatsinks, electromagnetic compatibility, electromagnetic coupling, HEAT SINK
  • Akdeniz Üniversitesi Adresli: Evet

Özet

High-speed switching capabilities of modern ICs cause generating more heat, and it must be ejected via metallic heat-sinks behaving as an antenna at certain frequencies. Having different radiation patterns(RP) at different frequencies may ca use a malfunction on nearby electronics placed on the other part of PCB. In this study, 50W equivalent heat-sink is investigated at 2-8 GHz in terms of feeding point. RP measurements and simulation results at four different feeding points are discussed, and it is observed that point of feeding is the pre-dominant factor of RP. As expected, the feeding of the heat-sinks from the center is to be preferred for lower frequencies, but it causes critical emission/interference problems at higher frequencies. As the frequency increases, it metamorphoses like a frog forming. While it behaves as an omnidirectional antenna having (similar to 2 dB) gain at 2GHz, RP turns to one that includes 6 beams with 30-degree beam-widths and (similar to 5 dB) gain.