Automotive Active Antenna Design for AM/FM Radio System

Olcay Yigit

Article Details

Automotive Active Antenna Design for AM/FM Radio System

Authors:

Olcay Yigit

Publisher:

Gazi University

Main Topics:

Mühendislik Elektromanyetiği

Journal:

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji Vol.13 Issue 3, pp.1062-1082

Document Type:

Article

Publication Date:

9/2025

Document Language:

Turkish

Document ID (Org No.):

2001353669

pISSN:

2147-9526

Keywords:

Abstract:

 This article examines the historical evolution of automobile antennas and highlights the importance of modern smart antenna designs. The long rod antennas, approximately 1.5 meters in length, used in the 1970s were replaced by active AMFM antennas integrated into vehicle windows starting in 1984. Today, spiral antenna designs measuring 5-15 cm in length are widely used to enhance antenna performance, provide aerodynamic advantages, and comply with electromagnetic compatibility regulations. The article also explores innovations such as antenna integration for digital video broadcasting DVB and V2X communication systems, high-impedance amplifiers with gains typically ranging from 15-25 dB, and triband antennas. The optimization of parameters such as impedance matching, gain, stability, and noise typically 1-2 dB during the active antenna design process is emphasized as crucial for improving antenna performance and electromagnetic immunity. As part of the study, a 40 cm rod antenna equipped with an amplifier operating in the AM and FM bands and with a noise level of 1.2 dB was designed. The antenna was tested on a vehicle, and the signal strength was measured using a Rigol Spectrum Analyzer. It was observed that the signal noise level was 1 dB lower compared to the original device. The helical structure of the designed antenna set the resonance frequency at 180 MHz. Additionally, the longer strip length compared to the antennas physical length reduced the capacitive input impedance, contributing to enhanced antenna performance through this key technical innovation.

 This article examines the historical evolution of automobile antennas and highlights the importance of modern smart antenna designs. The long rod antennas, approximately 1.5 meters in length, used in the 1970s were replaced by active AMFM antennas integrated into vehicle windows starting in 1984. Today, spiral antenna designs measuring 5-15 cm in length are widely used to enhance antenna performance, provide aerodynamic advantages, and comply with electromagnetic compatibility regulations. The article also explores innovations such as antenna integration for digital video broadcasting DVB and V2X communication systems, high-impedance amplifiers with gains typically ranging from 15-25 dB, and triband antennas. The optimization of parameters such as impedance matching, gain, stability, and noise typically 1-2 dB during the active antenna design process is emphasized as crucial for improving antenna performance and electromagnetic immunity. As part of the study, a 40 cm rod antenna equipped with an amplifier operating in the AM and FM bands and with a noise level of 1.2 dB was designed. The antenna was tested on a vehicle, and the signal strength was measured using a Rigol Spectrum Analyzer. It was observed that the signal noise level was 1 dB lower compared to the original device. The helical structure of the designed antenna set the resonance frequency at 180 MHz. Additionally, the longer strip length compared to the antennas physical length reduced the capacitive input impedance, contributing to enhanced antenna performance through this key technical innovation.

 This article examines the historical evolution of automobile antennas and highlights the importance of modern smart antenna designs. The long rod antennas, approximately 1.5 meters in length, used in the 1970s were replaced by active AMFM antennas integrated into vehicle windows starting in 1984. Today, spiral antenna designs measuring 5-15 cm in length are widely used to enhance antenna performance, provide aerodynamic advantages, and comply with electromagnetic compatibility regulations. The article also explores innovations such as antenna integration for digital video broadcasting DVB and V2X communication systems, high-impedance amplifiers with gains typically ranging from 15-25 dB, and triband antennas. The optimization of parameters such as impedance matching, gain, stability, and noise typically 1-2 dB during the active antenna design process is emphasized as crucial for improving antenna performance and electromagnetic immunity. As part of the study, a 40 cm rod antenna equipped with an amplifier operating in the AM and FM bands and with a noise level of 1.2 dB was designed. The antenna was tested on a vehicle, and the signal strength was measured using a Rigol Spectrum Analyzer. It was observed that the signal noise level was 1 dB lower compared to the original device. The helical structure of the designed antenna set the resonance frequency at 180 MHz. Additionally, the longer strip length compared to the antennas physical length reduced the capacitive input impedance, contributing to enhanced antenna performance through this key technical innovation.

 Bu makale, otomobil antenlerinin tarihsel gelişimini ve günümüz akıllı anten tasarımlarının önemini incelemektedir. 1970lerde kullanılan yaklaşık 1.5 metre uzunluğundaki çubuk antenlerin yerini, 1984ten itibaren araç camlarına entegre edilen aktif AMFM antenler almıştır. Günümüzde ise 5-15 cm boyutlarındaki sarmal anten tasarımları, anten performansını artırmak, aerodinamik avantaj sağlamak ve elektromanyetik uyumluluk düzenlemelerine uyum göstermek için yaygın olarak kullanılmaktadır. Makale, sayısal video yayını SVY ve V2X iletişim sistemleri gibi modern uygulamalara yönelik anten entegrasyonu, yüksek empedanslı amplifikatörler 15-25 dB kazanç ve triband antenler gibi yeniliklere de değinmektedir. Aktif anten tasarım sürecinde empedans uyumu, kazanç, kararlılık ve gürültü gibi parametrelerin optimize edilmesinin, anten performansını ve elektromanyetik bağışıklığı artırmak için kritik olduğu vurgulanmıştır. Çalışma kapsamında, AM ve FM bantlarında çalışan, 1.2 dB gürültü seviyesine sahip bir yükseltici ile donatılmış 40 cm boyunda bir çubuk anten tasarlanmıştır. Anten, araç üzerinde test edilmiş ve alınan sinyalin güç değeri Rigol Spectrum Analizör ile ölçülmüştür. Orijinal cihazla kıyaslandığında sinyalin gürültü seviyesinin 1 dB daha düşük olduğu gözlenmiştir. Tasarımda kullanılan helisel yapı, rezonans frekansını 180 MHze ayarlamış ve şerit boyunun anten boyundan uzun olması sayesinde kapasitif giriş empedansını düşürmüştür. Bu, antenin performansını artıran önemli bir teknik yenilik olarak öne çıkmıştır.

Article Details

Automotive Active Antenna Design for AM/FM Radio System

Authors:

Olcay Yigit

Publisher:

Gazi University

Main Topics:

Mühendislik Elektromanyetiği

Journal:

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji Vol.13 Issue 3, pp.1062-1082

Document Type:

Article

Publication Date:

9/2025

Document Language:

Turkish

Document ID (Org No.):

2001353669

pISSN:

2147-9526

Automotive antennas

rod atennas

AM/FM radio systemsOtomotiv Antenleri

Çubuk antenleri

AM/FM radyo sistemleri

Issues

Article Details

Automotive Active Antenna Design for AM/FM Radio System

Authors: Olcay Yigit

Publisher: Gazi University

Main Topics: Mühendislik Elektromanyetiği

Journal: Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji Vol.13 Issue 3, pp.1062-1082

Document Type: Article

Publication Date: 9/2025

Document Language: Turkish

Document ID (Org No.): 2001353669

pISSN: 2147-9526

Automotive antennas

rod atennas

AM/FM radio systemsOtomotiv Antenleri

Çubuk antenleri

AM/FM radyo sistemleri

Issues

Authors:

Olcay Yigit

Publisher:

Gazi University

Main Topics:

Mühendislik Elektromanyetiği

Journal:

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji Vol.13 Issue 3, pp.1062-1082

Document Type:

Article

Publication Date:

9/2025

Document Language:

Turkish

Document ID (Org No.):

2001353669

pISSN:

2147-9526