Antenna Engineering CHO, Yong Heui

Basics of Antenna Engineering

Antenna EngineeringAntenna Engineering

CHO, Yong HeuiCHO, Yong Heui


Introduction (교재소개)

Warren L. Warren L. StutzmanStutzman and Gary A. Thiele, "Antenna and Gary A. Thiele, "Antenna Theory and Design," 3rd ed., Wiley, 2012.Theory and Design," 3rd ed., Wiley, 2012.

0. Text

EM Wave LabEM Wave Lab2

Constantine A. Balanis, "Antenna Theory: Analysis and Design," 2nd ed., John Wiley & Sons, 1996.

Kin-Lu Wong, "Compact and Broadband Microstrip Antennas," John Wiley & Sons, 2002.

Antenna EngineeringAntenna Engineering1. Microwave Systems

Transmission

� � Information- Channel bandwidth- Base band- Inefficient wave radiation


� Modulation – center frequency

Time domain Frequency domain

출처: RFDH.com


Why do we need modulation?

� � Transmission efficiency- Multiplexing- Antenna length: wavelength- Wave radiation: comparison with DC

1. Microwave Systems


Battery: DCAntenna: AC


Microwave transmitter (Tx)

� � Up-conversion: frequency



( ))cos()cos(2

1)cos()cos( yxyxyx −++=

BBf BBLO ff ± BBLO ff ±

�

출처: RFDH.com


Microwave receiver (Rx)

� � Down-conversion: frequency


출처: RFDH.com


( ))cos()cos(2

1)cos()cos( yxyxyx −++=

BBfBBIF ff ±BBLO ff ±

IFLO fff −= IFff =

�


Microwave transceiver

� � Duplexer: bandpass filter or switch- Loss, tx suppression, channel selection


출처: RFDH.com


IF: superheterodyneNo IF: direct conversion


Antenna


� � Important passive device� Innovation



Aegis combat system: S-band


� � SPY-1(1974): phased array radar, smart antenna� 4 phased array radars, 3.6m x 3.6m, 4350 elements



Phased array radar


� � S-band: 2 ~ 4 GHz� Cost: about half billion $


Several megawatts radar�


SBX (Sea Based X-band radar)


� � X-band: 8 ~ 12 GHz� Cost: about 1 billion $� Norway, Russia, and USA� Missile Defense: early warning radar – SBX –

ground based interceptor


ground based interceptor


Hertz antenna (1886)

2. Antennas



RC circuits

2. Antennas



Simple model for antenna

2. Antennas


Antenna EngineeringAntenna Engineering2. Antennas

Dipole antenna

� � Simple but long structure� Low efficiency


Microstrip type


Loop antenna

2. Antennas

� � Simple structure� Low efficiency



First mobile phone

• Dr. Martin Cooper on 1973

• Motorola

• 850 [g]

2. Antennas



Helical antenna

2. Antennas

� � Complicated structure� Medium efficiency


Handy phone antenna


Triple band antenna

2. Antennas



Array antenna

� � Complicated structure� High efficiency

2. Antennas


Yagi antenna: one source


Microstrip patch antenna

2. Antennas

� � Simple and small structure� Low efficiency



Antenna simulation

Ansoft: Ensemble

2. Antennas


Ansoft: Ensemble

CST: MWS

Ansoft: HFSS


무역위원회 2008년보고서

3. Industrial Trend

� 2007년무역수지 5천6백만$적자� 안테나의분류

� 이동통신용� 기지국용� 자동차용


� 자동차용� 위성방송수신용� 선박용레이다

출처: 무역위원회

Antenna EngineeringAntenna Engineering3. Industrial Trend

안테나산업구조

�


세계안테나시장- 31억9천만$(2007년)- 37억2천만$(2009년예상)

�


휴대폰안테나산업의경쟁력



기지국안테나산업의경쟁력



안테나산업의 SWOT 분석



안테나산업의문제점과대응방안

� 국내3G 이동통신서비스설비투자감소� 대�중소기업상생협력중요산업� 전형적인소량다품종산업� 원천기술및지적재산권글로벌기업독점� 국내통신장비산업취약


� 국내통신장비산업취약

� 신규무선통신서비스투자확대유도� 안테나관련R&D 정책자금지원확대� 대�중소기업상생협력지원� 안테나산업의전략적육성지원� 국내Wibro 등무선통신기기장비산업지원

Antenna Engineering CHO, Yong Heui

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