Filtrujc antny Typical planar antenna Can be all the functions - PowerPoint PPT Presentation

Filtrující antény

Typical planar antenna Can be all the functions accomplished by a single  structure? frequency spatial impedance filter filter matching VERDU, J., PERRUISSEAU-CARRIER, J., COLLADO, C., MATEU, J., HUELTES, A. Microstrip patch antenna integration on a band-pass filter topology. In proc. 12th Mediterranean Microwave Symposium (MMS2012) , no. EPFL-CONF-179874. 2012. raida@feec.vutbr.cz 2

Planar filter Impedance discontinuities    forward and backward waves: - Pass-band: constructive interferences - Transmission line: d / dt raida@feec.vutbr.cz 3

Bandpass filter If x =  /2 …  raida@feec.vutbr.cz 4

Patch array, serial feeding       2       A A S D , AF , 1 S     21 11 Currents on patches  radiated waves:  - Main lobe: constructive interferences - Antenna: int( dt ) raida@feec.vutbr.cz 5

Inspiration Last resonator in the filter replaced by  an antenna WU, W. J., YIN, Y. Z., ZUO, S. L., ZHANG, Z. Y., XIE, J. J. A new compact filter-antenna for modern wireless communication systems. IEEE Antennas and Wireless Propagation Letters. vol. 10. DOI: http://dx.doi.org/10.1109/lawp.2011.2171469 raida@feec.vutbr.cz 6

Patch array & apertures raida@feec.vutbr.cz 7

Equivalent circuit raida@feec.vutbr.cz 8

Equivalent circuit Apertures in ground Planar plane antennas Transmission line raida@feec.vutbr.cz 9

Equivalent circuit Apertures in Planar  3 parallel RLC resonators ground plane antennas    j RL   A B 1        2 R RLC j L     C D   0 1   Transmission line  3 J inverters   1    A B 0    jJ     C D   jJ 0     4 segments of           A B cosh l Z sinh l transmission line  c           C D Y sinh l cosh l     c raida@feec.vutbr.cz 10

Equivalent circuit Apertures in Planar ground plane antennas Transmission line    A BY CZ D  S 0 0 11    A BY CZ D 0 0 raida@feec.vutbr.cz 11

Synthesis of filtering array o Patch array  band-pass filter (BPF) o Synthesis of BPF  requested transmission characteristics to be obtained            2       A A S D AF 1 S    21 11 raida@feec.vutbr.cz 12

Synthesis of filtering array o Low-pass prototype: normalized element values g n available to obtain requested characteristics o Band-pass antenna: coefficients re-computed comprising: o Required value of reflection coefficient o Acceptable level of fractional bandwidth raida@feec.vutbr.cz 13

Bandpass filter HONG, J. S., LANCASTER, M. J., Microstrip Filters for RF/Microwave Applications , New York: J. Wiley and Sons, 2001. ISBN: 0-471-38877-7. raida@feec.vutbr.cz 14

Filtering array o An example for 4 antenna elements, |S 11 | < – 10 dB and 0.08 < FBW s < 0.10               2 1 2 1 . 981 1 . 981 4 1 . 770 10 6 . 892 10 FBW  s FBW      1 2 1 . 770 10  g  g 1 0 5           2 2 1 1 g g 1 . 354 10 FBW 1 . 173 10 FBW 3 . 143 10 1 4          2 2 1 g g 3 . 257 10 FBW 1 . 759 FBW 3 . 708 10 2 3   2   A A S D AF 1 S     21 11 raida@feec.vutbr.cz

Transformace pásmová propust                  C L g C 0    serial   S 0   FBW FBW     0 0   FBW 1       C    2 1 FBW S    g    0 C 0 0 fractional bandwidth    g    C C parallel       P   FBW 0 1 2   0 0    FBW bandpass edge    0 L   P frequencies   g   0 C

Design o Known normalized element values g n  values of capacitances C and inductances L in equivalent circuit can be computed o Known C and L  dimensions of planar equivalents can be obtained raida@feec.vutbr.cz 17

Test case 1 f 0 = 4.8 GHz; FBW s = 8 %; S 11 < – 15 dB raida@feec.vutbr.cz 18

Test case 1 f 0 = 4.8 GHz; FBW s = 8 %; S 11 < – 15 dB raida@feec.vutbr.cz 19

Test case 2 f 0 = 5.8 GHz; FBW s = 12 %; S 11 < – 10 dB raida@feec.vutbr.cz 20

Test case 2 f 0 = 5.8 GHz; FBW s = 12 %; S 11 < – 10 dB raida@feec.vutbr.cz 21

Test case 3 f 0 = 6.8 GHz; FBW s = 12 %; S 11 < – 20 dB raida@feec.vutbr.cz 22

Test case 3 f 0 = 6.8 GHz; FBW s = 12 %; S 11 < – 20 dB raida@feec.vutbr.cz 23

Test samples raida@feec.vutbr.cz 24

Test case 1 f 0 = 4.8 GHz; FBW s = 8 %; S 11 < – 15 dB raida@feec.vutbr.cz 25

Test case 1 f 0 = 4.8 GHz; FBW s = 8 %; S 11 < – 15 dB E-plane H-plane

Test case 1 f 0 = 4.8 GHz; FBW s = 8 %; S 11 < – 15 dB raida@feec.vutbr.cz 27

Test case 2 f 0 = 5.8 GHz; FBW s = 12 %; S 11 < – 10 dB raida@feec.vutbr.cz 28

Test case 2 f 0 = 5.8 GHz; FBW s = 12 %; S 11 < – 10 dB E-plane H-plane

Test case 2 f 0 = 5.8 GHz; FBW s = 12 %; S 11 < – 10 dB raida@feec.vutbr.cz 30

Test case 3 f 0 = 6.8 GHz; FBW s = 12 %; S 11 < – 20 dB raida@feec.vutbr.cz 31

Test case 3 f 0 = 6.8 GHz; FBW s = 12 %; S 11 < – 20 dB E-plane H-plane

Test case 3 f 0 = 6.8 GHz; FBW s = 12 %; S 11 < – 20 dB raida@feec.vutbr.cz 33

Other filtenna concepts  Low-pass filter enforced to radiate: 1. Fractal DGS antenna  Multi-objective synthesis in frequency and space: 2. Dipole array 3. SIW-fed patch array raida@feec.vutbr.cz 34

Fractal DGS  Filter parameters - Bandwidth (-3 dB): 5.7 % - S 21 in pass band: ≈ -4.4 dB - S 21 in stop band: ≈ -40.0 dB - S 11 in pass band: ≈ -15.0 dB  Antenna parameters - Realized gain in pass band: ≈ 9.0 dB - Bandwidth (-10 dB): 1.7 % - Max. main lobe deflection (pass band): ≈ 5.0° raida@feec.vutbr.cz 35

Fractal DGS raida@feec.vutbr.cz 36

Dipole array  Frequency filtering 4NEC - Impedance match: ̵ 10 dB (pass) - Gain response: 13.0 dBi (pass), 5.0 dBi (stop)  Spatial filtering - Sidelobe level: 6 dBi (pass), 2 dBi (stop) - Main lobe deflection:  5.0 ° raida@feec.vutbr.cz 37

Dipole array  4NEC: Pareto front of optimal solutions  Tuning space-mapping: CPU-expensive CST model 38

Dipole array 39

Dipole array 40

Dipole array 41

SIW array raida@feec.vutbr.cz 42

SIW array 43

SIW array raida@feec.vutbr.cz 44