input hf-6m bp-lp filters for sdr transceivers - yu1lm

HF/50MHz Receiving and Low Power Transmitting Band Pass-Low Pass Filters for SDR transceivers Genesis G****, AVALA**, ADTRX** and HF transceiver CER-01 By dipl. ing. Tasić Siniša –Tasa YU1LM/QRP All rights reserved, project is free for personal use only SDR subject has some specific requirements compared to classic RX/TX design. All SDR receivers as DC (direct conversion) receivers are sensitive more or less to the harmonic receiving. My SDR receivers including receivers built in SDR transceivers AVALA series have also sensitivity to harmonic receiving. I made this test at the very beginning but for the very low frequencies below 2MHz and results was good from my point of view 20-35 dB rejection odd harmonics and more than 35dB even harmonics, results are comparable with receivers with moderate input filters. I declare that it is possible receiving with my SDR receivers without input filters and practical experience confirm this but it is partly true. I received very interesting mail from Tim DJ4JM who told me that had been measured results little over 10 dB lower sensitivity for third harmonic for DR2A+ 7MHz receiver. I check these measurements again and obtain little better results but only 15dB for third and 34dB for second harmonic. My practical experiences with all my SDR RXs are that harmonic receiving exist and that it is negligible even with my big antenna such 84m delta loop is. Receiving at 1.8MHz band I can hardly detect in the evenings hours presents of very strong broadcast stations from 5 and 7MHz band. Only extremely strong carriers are visible and noticeable. Because of that some kind of filter LP (low pass) or better BP (band-pass) are welcome and they will improve overall characteristics of all previously published SDR RX. The second problem is in connection with SDR transmission. I published several transmitters/modulators with CMOS switches series 74HC4053, 74HC4066 [1] and all are working better than any other types I tested before when we are talking about linearity at fundamental frequency. This realization has specific that modulator is working digitally that mean it has a lot of odd harmonics also modulated of course lower level than wanted output signal. The problem becomes serious when this spectrum arrives to RF linear power amplifier. To keep on unchanged output spectrum it is necessary to attached amplifier with extremely wide working bandwidth what it is no true in case RF amplifier I am using. All used RF amplifiers have limited bandwidth to 60-80 MHz maximum. The final results we have even harmonics hardly noticeable in output modulator terminate with resistive termination 50Ohms.The bigger problem is products around output signal which is results this harmonics and unwanted phase shift in RF power amplifier at harmonic frequencies. It is interesting that odd harmonics not third only as we are expecting but higher order 5, 7 become problem (see spectrum at picture below). Builders who first assembled my mono-band SDR transceiver AVALA-01 Bodo DJ9CS noticed problems measuring output spectrum from power amplifier with IRF510. He proposed solution which LP filter which dramatically improve output spectrum see picture below also. I made changes in all my new designs and added LP as option for RX and necessary part for the transmitters section (see new version of AVALA-01 and new AVALA-02). Of course it is possible to add BP filters as best solution but also as most complicate for practically realization. Here down in article there are two proposals for LP and four for BP. All filters are possible solder at PCB layout ADTRX**AVALA** and Genesis*** transceivers or on separate board with RF power amplifier. The filters target specification at start ware:

1. Filters are with maximum IL(insertion loss) lower than 2.5 dB with inductors Qo ~60 2. All filter components values have to be standard values. 3. Coils are without taps! 4. Termination return loss S11, S22 have to better as possible target value -20dB (VSWR=1.22). 5. Frequencies harmonically related to central frequency from upper side are attenuated ~20-30dB or more. For BP filters this

target value is from the lower side fo/2 ~20-30dB. 6. BP/LP filters have 50Ohms termination impedance and filters are symmetrical structure and it is not important what is input

or output. 7. Calculated bandwidth -3dB 5-25% of central frequency 8. All filter BP/LP variation is possible solder at the same PCB AVALA transceivers 9. No tune design with low sensitivity to the components tolerance.

Output spectrum at output SDR transceiver AVALA-01 (Pout 35.67dBm (4.2W) without LP/BP at modulator output

Output spectrum at output SDR transceiver AVALA-01 the same conditions as it is on picture up (Pout 38.6dBm (8.2W) ) with 2 L section LP/BP at modulator output

1. LP(low pass) with 2 coils

Fc -3dB [MHz][band]

L1,L2[uH]

C1A,C1B[pF]

C2[pF]

2.5 [1.8] 4,7 1800 3300 5.3 [3,5] 2,2 820 1500 8 [5,7] 1,2 470 820 15 [10.1,14] 0,680 270 470 25 [18,21] 0,39 150 270 35 [24,28] 0,33 120 220 57 [50] 0,18 68 120

0.1 2.1 4.1 6.1 8.1 10Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

10 MHz-38.87 dB

7.0079 MHz-20.09 dB

5.2896 MHz-3.352 dB

2.0844 MHz-0.04375 dB

7.012 MHz-58.7 dB

10 MHz-74.7 dB

3.5015 MHz-24.6 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

Picture1. LP (low pass) filter for 1.8MHz and 3.5(5.3) MHz

0.1 10.1 20.1 30Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

21.06 MHz-46.46 dB

14.05 MHz-25.96 dB

20.46 MHz-15.07 dB

8.867 MHz-0.01708 dB

14.07 MHz-0.002292 dB

28.15 MHz-33.07 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

Picture2. LP (low pass) filter for 7MHz and 10(14) MHz

0.1 20.1 40.1 60.1 80.1 100Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

25.537 MHz-0.05557 dB

62.341 MHz-44.42 dB

42.181 MHz-24.47 dB

36.334 MHz-15.77 dB

100 MHz-57.39 dB

55.943 MHz-29.3 dB

32.456 MHz-0.5398 dB

83.524 MHz-49.04 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

Picture3. LP (low pass) filter for 18MHz and 21,25,28 MHz

0.1 50.1 100.1 150Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

144.3 MHz-47.39 dB

100 MHz-29.19 dB

55.94 MHz-0.1476 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

Picture4. LP (low pass) filter for 50MHz

2. LP(low pass) with 3 coils

Fc -3dB [MHz][band]

L1 [uH]

L2 [uH]

L3 [uH]

C1pF]

C2[pF]

C3[pF]

C4 pF]

2.5 [1.8] 4,7 5,6 4,7 1200 2700 2700 1200 5.3 [3,5] 2,7 3,3 2,7 560 1200 1200 560 8 [5,7] 1,5 1,8 1,5 330 680 680 330 15 [10.1,14] 0,680 0,820 0,680 180 390 390 180 25 [18,21] 0,47 0,56 0,47 100 220 220 100 35 [24,28] 0,33 0,43 0,33 47 150 150 47 57 [50] 0,22 0,27 0,22 39 100 100 39

0.1 2.1 4.1 6.1 8.1 10Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

2.0781 MHz-0.01637 dB

7.2588 MHz-81.01 dB

2.0176 MHz-26.83 dB

3.522 MHz-31.01 dB DB(|S(1,1)|)

lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

0.1 5.1 10.1 15.1 20Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

14.13 MHz-80.24 dB

6.982 MHz-32.46 dB

4.027 MHz-26.63 dB

4.07 MHz-0.00703 dB

10.52 MHz-61.17 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

0.1 10.1 20.1 28Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

10.1 MHz-15.1 dB

21.26 MHz-69.84 dB

7.006 MHz-0.2219 dB

7.309 MHz-22.21 dB

7.003 MHz-21.4 dB

14.02 MHz-41.52 dB

7.4 MHz-0.2291 dB

DB(|S(1,1)|)Schematic 1



0.1 10.1 20.1 30.1 40.1 50Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

14.48 MHz-22.28 dB

42.13 MHz-70.38 dB

15.77 MHz-0.2724 dB

22.23 MHz-24.21 dB

28.1 MHz-42.51 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

0.1 20.1 40.1 60.1 80.1 100Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

63.663 MHz-65.6 dB

22.37 MHz-24.55 dB

21.542 MHz-0.01695 dB

42.169 MHz-37.28 dB

54.862 MHz-55.72 dB

36.883 MHz-27.04 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

0.1 50.1 100.1 150Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

33.91 MHz-0.2649 dB

30.01 MHz-33.36 dB

144.3 MHz-89.16 dB

100 MHz-66.59 dB

55.94 MHz-29.6 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

0.1 50.1 100.1 150Frequency (MHz)

trans

-100

-80

-60

-40

-20

0

50.17 MHz-0.008012 dB

50.01 MHz-28.73 dB

144.3 MHz-66.62 dB

100 MHz-42.47 dB

54.91 MHz-0.585 dB

DB(|S(1,1)|)lp

DB(|S(2,1)|)lp

DB(|S(2,2)|)lp

3. A New BP(band pass) filter with 3 coils BP-LP YU1LM

This band pass filter realization is something new. I didn’t see something similar in literature ever before. This filter offers very good performances but it is sensitive to component variation if we like to build very narrow filters. This statement is related to precise values of C3 and C4 capacitors. Filter is ideal for SMT component use especially for critical components.

BAND L[uH] L2[uH] L3[uH ] C1[pF] C2[pF] C3[pF] C4[pF] C5[pF] C6[pF] 1.8MHz 12 1.8 12 470 100 6800 6800 100 470 3.5MHz 4.7 1 4.7 330 82 3300 3300 82 330 7MHz 2.2 0.27 2.2 180 82 3900 3900 82 180 10MHz 1.2 0.15 1.2 150 82 3300 3300 82 150 14MHz 1 0.091 1 82 33+18 2700 2700 33+18 82 10-14MHz 0.82 0.43 0.82 220 56 680 680 56 220 14-18MHz 0.56 0.22 0.56 150 68 820 820 68 150 18-21MHz 0.39 0.12 0.39 120 82 1000 1000 82 120+15 21-24MHz 0.33 0.1 0.33 100 68 820 820 68 100 24-28MHz 0.33 68nH 0.33 68 47 910 910 47 68 50MHz 0.15 33nH 0.15 47 33 560 560 33 47 50MHz* 0.1 6,8nH 0.1 33 68 2700 2700 68 33

Table1. Element values for BP filters with 3coils BP-LP-YU1LM (*Super-selective BP)

0.1 1.1 2.1 3.1 4.1 5Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

1.99 MHz-25.87 dB

1.811 MHz-19.91 dB

1.005 MHz-32.92 dB

1.504 MHz-15.31 dB

2 MHz-2.229 dB

3.508 MHz-48.93 dB

1.82 MHz-2.639 dB




BP for 1.8MHz with molded chokes Qo~60

0.1 1.1 2.1 3.1 4.1 5Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

1.99 MHz-28.92 dB

1.811 MHz-20.98 dB

1.005 MHz-32.9 dB

1.504 MHz-15.14 dB

2 MHz-1.529 dB

3.508 MHz-48.81 dB

1.82 MHz-1.848 dB DB(|S(1,1)|)

Schematic 1



BP for 1.8MHz with ring core Qo~180

1 3 5 7 9 10Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

10 MHz-67.33 dB

4.0038 MHz-22.35 dB

3.5047 MHz-26.01 dB

1.8431 MHz-28.47 dB

7 MHz-46.52 dB

4.0151 MHz-1.514 dB

3.5083 MHz-1.532 dB




BP for 3,5MHz with molded chokes Qo~60

1 6 11 16 21Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

7.015 MHz-36.43 dB

3.53 MHz-33.43 dB

14.07 MHz-60.09 dB

10.16 MHz-36.9 dB

1.843 MHz-45.04 dB

7 MHz-1.577 dB




BP for 7MHz with molded chokes Qo~60

1 6 11 16 21Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

7.015 MHz-34.84 dB

3.53 MHz-33.4 dB

14.07 MHz-60.07 dB

10.16 MHz-36.81 dB

1.843 MHz-45.03 dB

7 MHz-0.7835 dB




BP for 7MHz with ring core Qo~180

1 11 21 30Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

20.21 MHz-58.34 dB

18.06 MHz-51.08 dB

14.02 MHz-31.04 dB

10.1 MHz-35.69 dB

10 MHz-1.394 dB

1.843 MHz-47.81 dB

7 MHz-20.18 dB

3.508 MHz-39.75 dB DB(|S(1,1)|)

Schematic 1





Graph 1

-80

-60

-40

-20

0

27.97 MHz-61.68 dB

21.07 MHz-41.06 dB

18.06 MHz-25.02 dB

14.02 MHz-1.534 dB

14 MHz-46.75 dB

10 MHz-25.11 dB

1.843 MHz-56.82 dB

7 MHz-38.53 dB

3.508 MHz-50.05 dB






Graph 1

-80

-60

-40

-20

0

10.1 MHz-19.32 dB

28.06 MHz-45.06 dB

21.07 MHz-26.29 dB

18.06 MHz-13.6 dB

14.35 MHz-0.8228 dB

14.5 MHz-25.23 dB

10 MHz-0.9006 dB

1.843 MHz-30.12 dB

7 MHz-9.588 dB

3.508 MHz-22.96 dB




BP for 10-14MHz with molded chokes Qo~60

1 11 21 31 41 50Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

36.25 MHz-50.28 dB

14.45 MHz-21.26 dB

18.21 MHz-22.93 dB

10.08 MHz-11.05 dB

28.06 MHz-33.19 dB

21.07 MHz-7.482 dB

18.28 MHz-0.9726 dB

14.35 MHz-0.8639 dB

14.03 MHz-27.01 dB

1.843 MHz-37.73 dB

7 MHz-21.22 dB

3.508 MHz-31.25 dB





1 11 21 31 41 50Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

21.01 MHz-28.07 dB

21.46 MHz-25.32 dB

42.17 MHz-51.2 dB

18.21 MHz-25.93 dB

10.08 MHz-19.95 dB

36.21 MHz-40.85 dB

21.62 MHz-0.9732 dB

18.28 MHz-0.9092 dB

14.35 MHz-6.765 dB

1.843 MHz-41.95 dB

7 MHz-27.26 dB

3.508 MHz-35.78 dB




BP for 18- 21MHz with molded chokes Qo~60

1 11 21 31 41 50Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

25.54 MHz-0.7821 dB

25.16 MHz-25.28 dB

21.46 MHz-28.28 dB

42.17 MHz-38.65 dB

10.08 MHz-24.9 dB

36.21 MHz-26.2 dB21.62 MHz

-0.782 dB18.28 MHz-4.243 dB

14.35 MHz-15.51 dB

1.843 MHz-44.43 dB

7 MHz-30.74 dB

3.508 MHz-38.44 dB






Graph 1

-80

-60

-40

-20

0

30.51 MHz-0.9018 dB

25.54 MHz-0.8498 dB

25.16 MHz-21.18 dB

30.1 MHz-27.81 dB

56.01 MHz-52.77 dB

10.08 MHz-33.35 dB

49.95 MHz-45.02 dB

21.62 MHz-7.586 dB

18.28 MHz-17.42 dB

14.35 MHz-26 dB

1.843 MHz-51.56 dB

7 MHz-38.43 dB

3.508 MHz-45.68 dB






Graph 1

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-60

-40

-20

0

52.49 MHz-25.43 dB

50.12 MHz-26.38 dB

144.1 MHz-72.64 dB

98.9 MHz-49.08 dB

30.51 MHz-18.71 dB

54.58 MHz-0.9441 dB

10.08 MHz-38.25 dB

49.95 MHz-0.8713 dB

21.62 MHz-27.71 dB

14.35 MHz-34.13 dB

1.843 MHz-53.96 dB

7 MHz-41.93 dB

3.508 MHz-48.29 dB





1 21 41 61 81 100Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

88.546 MHz-58.81 dB

57.305 MHz-4.833 dB

46.872 MHz-4.856 dB

52.492 MHz-26.58 dB

50.116 MHz-20.56 dB

100 MHz-67.64 dB

30.512 MHz-38.05 dB

54.585 MHz-1.819 dB

10.083 MHz-57.25 dB

49.948 MHz-1.723 dB

21.619 MHz-46.87 dB

14.352 MHz-53.17 dB

1.8431 MHz-72.93 dB

7 MHz-60.92 dB

3.5083 MHz-67.26 dB




BP for 50-52MHz with molded chokes Qo~60, super-selective realization is very ‘touchy” to the component variation!

4. BP with 2 coils

This type of filters I published in several articles at WEB pages. Published BP filters were with 3 coils which offer much more freedom in design than with 2 coils especially if want obtain wider BP this type is very good for narrow BP type. These filters for wide bandwidth are not so good they have moderate selectivity. It is hard expect more from 2 coils only.

BP filter with 2 coils

BAND L1[uH] L2[uH] C1[pF] C2[pF] C3[pF] C4[pF] C5[pF] C6[pF] C7[pF] 1.8MHz 10 10 3300 1000 680 270 680 1000 3300 3.5MHz 4.7 4.7 560 390 560 240 560 390 560 7MHz 2.7 2.7 330 220 240 68 240 220 330 10MHz 1.5 1.5 220 220 220 56 220 220 220

14MHz 1 1 150 150 180 56 180 150 150 18-21MHz 0.68 0.68 470 150 100 56 100 150 470

21-24MHz 0.33 0.68 0.33 100 68 820 820 68 100

24-28MHz 0.47 0.47 560 91 68 56 68 100 560 28MHz 0.33 0.33 180 150 120 47 120 150 180 50MHz 0.22 0.22 68 68 56 18 56 68 68

0.1 2.1 4.1 6.1 7.2Frequency (MHz)

Graph 1

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-60

-40

-20

0

2.065 MHz-21.4 dB1.812 MHz

-20.38 dB

2.102 MHz-1.881 dB

1.004 MHz-19 dB

1.506 MHz-7.151 dB

7 MHz-62.85 dB

1.843 MHz-1.563 dB

3.508 MHz-32.35 dB DB(|S(1,1)|)

Schematic 1




0.1 5.1 10.1 11Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

3.822 MHz-1.234 dB

3.847 MHz-20.99 dB

3.498 MHz-21.41 dB

11 MHz-55.91 dB

11 MHz-55.91 dB

1.843 MHz-25.9 dB

7 MHz-38.2 dB

3.508 MHz-1.22 dB





0.1 5.1 10.1 15.1 20.121Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

7.355 MHz-1.231 dB

10.09 MHz-25.63 dB

7.002 MHz-29.96 dB

7.309 MHz-25.71 dB

21 MHz-58.18 dB

14 MHz-42.05 dB

1.843 MHz-37.48 dB

7 MHz-1.119 dB

3.508 MHz-28.43 dB





0.1 10.1 20.1 30.131Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

14 MHz-25.84 dB

20.21 MHz-45.38 dB

10.02 MHz-23.99 dB

10.42 MHz-25.58 dB

24.78 MHz-54.01 dB

28.43 MHz-59.58 dB

10.08 MHz-1.349 dB

14.66 MHz-28.93 dB

1.843 MHz-43.7 dB

7 MHz-22.45 dB

3.508 MHz-36.63 dB





0.1 10.1 20.1 30.1 40.142Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

14 MHz-1.228 dB

21.25 MHz-29.86 dB

14.11 MHz-26.99 dB

14.58 MHz-29.11 dB

24.78 MHz-37.96 dB

28.43 MHz-44.22 dB

10.08 MHz-19.81 dB

42 MHz-60.18 dB

14.66 MHz-1.237 dB

1.843 MHz-45.53 dB

7 MHz-29.75 dB

3.508 MHz-39.2 dB





0.1 10.1 20.1 30.1 40.142Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

21 MHz-29.4 dB

18.16 MHz-21.59 dB

41.17 MHz-38.92 dB

21.45 MHz-20.28 dB

35.73 MHz-31.6 dB

18.04 MHz-19.74 dB

14 MHz-6.715 dB

18.24 MHz-0.7866 dB

28 MHz-16.92 dB

21.16 MHz-0.8368 dB

10.11 MHz-14.15 dB

7 MHz-19.38 dB

1.816 MHz-32.5 dB

3.508 MHz-26.53 dB





0.1 20.1 40.1 60Frequency (MHz)

BP 24-30MHz

-80

-60

-40

-20

0

28.06 MHz-23.03 dB

50.7 MHz-27.42 dB

24.87 MHz-0.5937 dB

56.05 MHz-32.67 dB

30.38 MHz-25.45 dB

24.9 MHz-22.21 dB

14 MHz-9.197 dB

18.24 MHz-4.683 dB

30.03 MHz-0.6137 dB

21.16 MHz-2.033 dB

10.11 MHz-13.44 dB

7 MHz-17.34 dB

1.816 MHz-29.59 dB

3.508 MHz-23.77 dB DB(|S(1,1)|)

Schematic 1





Graph 1

-80

-60

-40

-20

0

28.07 MHz-29.14 dB

28.02 MHz-0.9721 dB

21.25 MHz-11.3 dB

30.05 MHz-21.96 dB

24.78 MHz-3.865 dB

56.18 MHz-42.7 dB

30.51 MHz-1.321 dB

10.08 MHz-26.59 dB

49.95 MHz-36.48 dB

14.35 MHz-21.56 dB

1.843 MHz-42.83 dB

7 MHz-30.59 dB

3.508 MHz-37.12 dB





1 21 41 61 81 100Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

88.546 MHz-37.16 dB

52.492 MHz-20.45 dB

50.116 MHz-25.3 dB

100 MHz-43.32 dB

30.512 MHz-22.42 dB

54.585 MHz-1.301 dB

10.083 MHz-37.84 dB

49.948 MHz-1.056 dB

21.619 MHz-28.98 dB

14.352 MHz-34.18 dB

1.8431 MHz-53.14 dB

7 MHz-41.3 dB

3.5083 MHz-47.5 dB DB(|S(1,1)|)

Schematic 1




5. BP with 2 coils the simplest solution ver1 This type BP filters I used several times it simple as possible solution for BP with minimum components but still very useful

realization. These filters for wide bandwidth are not so good they have moderate selectivity. It is hard expect more selectivity from 2 coils and few capacitors only.

BP with 2 coils ver1

BAND L1[uH] L2[uH] C1[pF] C2[pF] C3[pF] C4[pF] C5[pF] 1.8MHz 8.2 8.2 680 390 3900 390 680 3.5MHz 5.6 5.6 330 91 1200 82 330 7MHz 2.7 2.7 150 82 1000 82 150 10MHz 2.2 2.2 100 39 560 39 100 14MHz 1.5 1.5 68 33 470 33 68 10-14MHz 1.2 1.5 220 47 270 10 150 14-18MHz 0.68 0.82 180 82 330 47 150 18-21MHz 0.47 0.47 120 82 470 91 120 21-24MHz 0.43 0.43 100 68 390 68 91 24-28MHz 0.39 0.39 82 47 270 47 82 28MHz 0.39 0.39 56 47 390 47 56 50MHz 0.18 0.18 39 33 220 33 39

0.2 2.2 4.2 6.2 7.2Frequency (MHz)

Graph 1

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-60

-40

-20

0

1.499 MHz-8.358 dB

2 MHz-25.34 dB

1.812 MHz-19.91 dB

1.002 MHz-21.15 dB

2.106 MHz-2.226 dB

7 MHz-55.36 dB

1.8 MHz-1.767 dB

3.508 MHz-30.82 dB DB(|S(1,1)|)

Schematic 1



BP for 1.8-2MHz with molded chokes Qo~60

0.1 5.1 10.1Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

3.994 MHz-22.53 dB

3.508 MHz-21.97 dB

10.07 MHz-41.08 dB

4.001 MHz-1.006 dB

1.002 MHz-28.25 dB

7 MHz-28.01 dB

1.8 MHz-20.06 dB

3.508 MHz-1.095 dB DB(|S(1,1)|)

Schematic 1



BP for 3.5-4MHz with molded chokes Qo~60

0.1 5.1 10.1 15.1 20.121Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

7.339 MHz-27.06 dB

20.95 MHz-50.58 dB

14.01 MHz-36.53 dB

7.322 MHz-1.202 dB

7.064 MHz-21.84 dB

10.07 MHz-21.09 dB

7 MHz-1.155 dB

1.8 MHz-34.07 dB

3.508 MHz-24.59 dB




BP for 7-7.3MHz with molded chokes Qo~60

0.1 10.1 20.1 30.131Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

10.1 MHz-22.15 dB

30.62 MHz-49.75 dB

20.28 MHz-35.68 dB

14.01 MHz-18.1 dB

7.018 MHz-14.6 dB

10.07 MHz-1.053 dB

1.8 MHz-36.86 dB

3.508 MHz-29.43 dB





0.1 10.1 20.1 30.1 40.142Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

14.46 MHz-28.24 dB

42 MHz-51.01 dB

14.46 MHz-0.9582 dB

14 MHz-28.07 dB

28.04 MHz-37.02 dB

21.09 MHz-24.1 dB

14.01 MHz-0.9609 dB

7.018 MHz-25.63 dB

10.07 MHz-15.53 dB

1.8 MHz-41.94 dB

3.508 MHz-35.34 dB





0.1 10.1 20.1 30.1 40.142Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

13.95 MHz-24.02 dB

10.14 MHz-15.16 dB

14.34 MHz-21.25 dB

42 MHz-40.22 dB

14.46 MHz-0.6046 dB

28.04 MHz-26.81 dB

21.09 MHz-15.51 dB

7.018 MHz-7.519 dB

10.07 MHz-0.7561 dB

1.8 MHz-25.09 dB

3.508 MHz-18.23 dB





0.1 20.1 40.1 54Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

18.17 MHz-20.62 dB

18.2 MHz-0.6152 dB

13.95 MHz-19.43 dB

14.34 MHz-19.08 dB

36.13 MHz-29.5 dB

14.46 MHz-0.5557 dB

28.04 MHz-18.91 dB

21.09 MHz-4.382 dB

7.018 MHz-12.93 dB

10.07 MHz-5.744 dB

1.8 MHz-28.06 dB

3.508 MHz-21.65 dB





0.1 20.1 40.1 54Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

42.16 MHz-32.87 dB

21.48 MHz-19.27 dB

18.17 MHz-24.85 dB

18.2 MHz-0.6741 dB

36.13 MHz-26.13 dB

14.46 MHz-5.537 dB

28.04 MHz-12.88 dB

21.66 MHz-0.7556 dB

7.018 MHz-20.72 dB

10.07 MHz-14.97 dB

1.8 MHz-34.57 dB

3.508 MHz-28.39 dB




BP for 18-21.5MHz with molded chokes Qo~60c

0.1 20.1 40.1 54Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

25.28 MHz-20.15 dB

25.5 MHz-0.7611 dB

50.03 MHz-34.06 dB

21.48 MHz-19.87 dB

18.2 MHz-3.294 dB

36.13 MHz-19.24 dB

14.46 MHz-10.77 dB

28.04 MHz-3.826 dB

21.66 MHz-0.5825 dB

7.018 MHz-23.46 dB

10.07 MHz-18.45 dB

1.8 MHz-36.77 dB

3.508 MHz-30.7 dB





0.1 20.1 40.1 60.1 80.1 100Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

83.979 MHz-44.97 dB

74.898 MHz-40.65 dB

30.022 MHz-25.69 dB

24.962 MHz-20.81 dB

25.154 MHz-0.4676 dB

56.19 MHz-29.36 dB

21.01 MHz-3.213 dB

50.029 MHz-24.37 dB

14.458 MHz-13.59 dB

30.232 MHz-0.4958 dB

7.018 MHz-23.99 dB

10.069 MHz-19.6 dB

1.8002 MHz-36.84 dB

3.5083 MHz-30.85 dB





0.1 20.1 40.1 60.1 80.1 100Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

21.064 MHz-10.27 dB

28.034 MHz-28.88 dB

83.979 MHz-49.44 dB

74.898 MHz-45.24 dB

30.022 MHz-31.05 dB

28.067 MHz-0.5714 dB

56.19 MHz-34.1 dB

50.029 MHz-29.05 dB

14.458 MHz-21.23 dB

30.232 MHz-0.6277 dB

7.018 MHz-31.37 dB

10.069 MHz-27.07 dB

1.8002 MHz-44.15 dB

3.5083 MHz-38.17 dB





0.1 50.1 100.1 150Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

54.67 MHz-25.03 dB

49.97 MHz-28.62 dB

21.06 MHz-22.23 dB

144.5 MHz-46.42 dB

101.4 MHz-32.14 dB

30.02 MHz-0.2101 dB

53.95 MHz-0.6492 dB

50.03 MHz-0.643 dB

14.46 MHz-27.11 dB

30.23 MHz-15.34 dB

7.018 MHz-34.4 dB

10.07 MHz-30.94 dB

1.8 MHz-46.5 dB

3.508 MHz-40.65 dB





5. BP with 2 coils the simplest solution ver2 This type BP filters I used several times it is simple as possible solution for BP with minimum components but still very

useful realization. This solution is similar to BP ver1 original idea for design going from 2m LP-BP from DJ8ES. These filters for wide bandwidth are not so good they have moderate selectivity. It is hard expect more selectivity from 2 coils and few capacitors only.

BP filter with 2 coils ver2

BAND L1[uH] L2[uH] C1[pF] C2[pF] C3[pF] C4[pF] C5[pF]

1.8MHz 10 10 1500 680 330 680 1500

3.5MHz 5.6 5.6 1000 330 91 330 1000

7MHz 2.7 2.7 560 180 47 180 560

10MHz 2.7 2.7 240 82 22 82 240

14MHz 1.5 1.5 240 82 22 82 240

14MHz ver1 1.5 1.5 270 82 18 82 270

18-21MHz 1 1 100 56 33 56 100

24-28MHz 0.68 0.68 82 47 27 43 82

50MHz 0.43 0.43 82 22 4.7 22 33+39

0.1 2.1 4.1 6.1 7.2Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

2.006 MHz-24.24 dB

1.811 MHz-24.12 dB

2.007 MHz-1.48 dB

1.004 MHz-11.49 dB

1.506 MHz-2.962 dB

7 MHz-67.33 dB

1.804 MHz-1.283 dB

3.508 MHz-34.05 dB DB(|S(1,1)|)

Schematic 1




0.1 5.1 10.110.5Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

10.48 MHz-63.23 dB

3.803 MHz-23.6 dB

3.542 MHz-22.72 dB

2.007 MHz-17.29 dB

1.506 MHz-20.95 dB

7 MHz-42.86 dB

3.809 MHz-1.056 dB

3.508 MHz-1.174 dB DB(|S(1,1)|)

Schematic 1




0.1 5.1 10.1 15.1 20.121Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

20.98 MHz-65.72 dB

14.01 MHz-45.38 dB

10.48 MHz-27.26 dB

7.329 MHz-21.03 dB

7.002 MHz-24.24 dB

1.789 MHz-25.83 dB

7 MHz-0.9818 dB

3.809 MHz-18.36 dB

7.357 MHz-0.9664 dB





0.1 10.1 20.1 30Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

30 MHz-60.29 dB

20.98 MHz-43.12 dB

14.01 MHz-18.76 dB

10.12 MHz-0.8286 dB

10.14 MHz-30.74 dB

1.789 MHz-31.86 dB

7 MHz-13.07 dB

3.809 MHz-24.08 dB





0.1 10.1 20.1 30.1 40.142Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

14.56 MHz-31.67 dB

41.98 MHz-64.12 dB

14.48 MHz-0.9209 dB

28.05 MHz-44.09 dB

21.09 MHz-26.9 dB

14.01 MHz-0.9248 dB

10.12 MHz-11.51 dB

14.03 MHz-30.66 dB

1.789 MHz-32.14 dB

7 MHz-18.9 dB

3.502 MHz-26.19 dB





0.1 10.1 20.1 30.1 40.142Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

14.56 MHz-29.5 dB

41.98 MHz-67.16 dB

14.48 MHz-1.052 dB

28.05 MHz-46.93 dB

21.09 MHz-29.41 dB

14.01 MHz-1.131 dB

10.12 MHz-14.27 dB

14.03 MHz-21.97 dB

1.789 MHz-33.9 dB

7 MHz-21.28 dB

3.502 MHz-28.11 dB




BP for 14MHz with molded chokes Qo~60 ver1

0.1 20.1 40.1 60.163Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

63 MHz-53.58 dB

18.08 MHz-26.67 dB

18.04 MHz-0.5409 dB

42.06 MHz-34.86 dB

21.52 MHz-24.8 dB

36.09 MHz-27.12 dB

28.05 MHz-12.4 dB

21.58 MHz-0.6196 dB

14.01 MHz-3.696 dB

10.12 MHz-10.1 dB

1.789 MHz-28.55 dB

7 MHz-15.25 dB

3.502 MHz-22.45 dB





0.1 30.1 60.1 90Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

28.04 MHz-21.16 dB

85.73 MHz-54.42 dB

24.85 MHz-0.618 dB

74.93 MHz-48.25 dB

24.91 MHz-24.74 dB

50.8 MHz-29.25 dB

29.9 MHz-19.06 dB

56.27 MHz-34.51 dB

30.03 MHz-0.8021 dB

21.58 MHz-1.647 dB

14.01 MHz-9.486 dB

10.12 MHz-13.91 dB

1.789 MHz-30.35 dB

7 MHz-17.9 dB

3.502 MHz-24.4 dB





0.1 50.1 100.1 150Frequency (MHz)

Graph 1

-80

-60

-40

-20

0

21.43 MHz-23.82 dB

53.9 MHz-1.128 dB

144.1 MHz-65.75 dB

100 MHz-47.26 dB

53.4 MHz-21.55 dB

50.8 MHz-1.06 dB

50.3 MHz-22.92 dB

30.03 MHz-19.34 dB

14.01 MHz-27.81 dB

10.12 MHz-30.63 dB

1.789 MHz-45.58 dB

7 MHz-33.79 dB

3.502 MHz-39.76 dB




BP for 50-52MHz with molded chokes Qo~60 August 2008, rewritten September 2009 VY 73/72 and GL in homebrew Tasa YU1LM/QRP [email protected]

References:

1. www.yu1lm.qrpradio.com 2. www.genesisradio.com.au 2. http://www.linear.com/designtools/software 4. M.Martin DJ7VY :A New Type of Preamplifier for 145 MHz and 435 MHz Receivers/UKW berichte 1/1978 5. www.dl5swb.de 6. Ed Wetherhold W3NQN – Clean Your Signal with Band-Pass Filter –part1 ), QST May 1998(pages 44-48) , 7. Ed Wetherhold W3NQN – Clean Your Signal with Band-Pass Filter –part1 ), QST June 1998(pages 30-42), 8. http://www.bavarian-contest-club.de/projects/bandpassfilter/100W-BP.pdf 9. http://www.atceramics.com/ 10. Lew Gordon K4VX-Band-Pass Filters for HF transceivers, QST September 1988 (pages 17-23)

input hf-6m bp-lp filters for sdr transceivers - yu1lm

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