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Type: Posts; User: ktr

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1. ## Thread: Lamda equals to how many degrees on smith chart

by ktr
Replies
19
Views
915

### Closed: Re: Lamda equals to how many degrees on smith chart

1 Ghz - 30 cm wavelength in air Epsilon = 1 -- 15cm wavelength in FR4 Epsilon= 4

1/sqrt(4) = 1/2 will be the velocity of wave in FR4 when compared to Air.

Electrical length in terms of S11,S22...
2. ## Thread: Suggestion to design a matching network

by ktr
Replies
4
Views
392

### Closed: Re: Suggestion to design a matching network

I'm not sure if thats what you want, but you can use an RF switch(SP6T or something like that) with a couple nanosec~switch time; and design different matching networks covering different frequencies.
3. ## Thread: Layout design book recommendation

by ktr
Replies
3
Views
261

### Closed: Re: Layout design book recommendation

-keep your traces about lambda/10 long in your circuit for phase stability.
-make sure to do em simulation to observe how your current travels through the PCB.
-use proper DC-block and RF-choke...
4. ## Thread: Microwave amplifier, component distance

by ktr
Replies
4
Views
284

### Closed: Re: Microwave amplifier, component distance

Easiest way for you to learn is, look at an eval board of a commercial amplifier at your frequency of interest. Download it's gerber file, and look at it's via placement and size. Analog Devices and...
5. ## Thread: Using a 0db Attn as termination

by ktr
Replies
3
Views
204

### [SOLVED]Closed: Re: Using a 0db Attn as termination

Hello Dr. Volker,

Thanks for replying. That's the part I'm struggling to figure out, if reasonable. If not properly terminated circulator does not work; hence I thought maybe a 0-db attenuator...
6. ## Thread: Using a 0db Attn as termination

by ktr
Replies
3
Views
204

### [SOLVED]Closed: Using a 0db Attn as termination

Hello Microwave Forum,

I am trying to incorporate a RF power detector in my circuit at C-band to understand if a discontinious cable or a rusty connector exists between my antenna and PA.

I...
7. ## Thread: 90 nm cmos 60 ghz and 130 nm

by ktr
Replies
2
Views
556

### Closed: Re: 90 nm cmos 60 ghz and 130 nm

you need to sign a confidentiality agreement with a foundry for them to share their production parameters with you. that sort of datasheet is hard to find online.
8. ## Thread: group delay of waveguides

by ktr
Replies
1
Views
310

### Closed: Re: group delay of waveguides

Because, waveguides are also frequency dependent in their own nature. When u design a waveguide or a transmission line, it actually works perfect for a single frequency. So, if your aim is to get a...
9. ## Thread: Negative voltage needed in K-band

by ktr
Replies
3
Views
1,483

### [SOLVED]Closed: Negative voltage needed in K-band

Hello,

I am trying to incorporate a medium power PA into my circuit, which had only positive voltages before that. For this PA, I need to include a negative gate voltage for active bias purposes....
10. ## Thread: Loop bandwidth of a Charge pump PLL

by ktr
Replies
1
Views
273

### Closed: Re: Loop bandwidth of a Charge pump PLL

PLL locks the free-running oscillator to a certain frequency using the VCO's tuning voltage pin by adjusting the voltage of that pin. PLL controls the output voltage of the charge pump so that VCO...
11. ## Thread: design band stop filter

by ktr
Replies
3
Views
644

### Closed: Re: design band stop filter

Maybe you can search the web for a filter design software like FilPro.
12. ## Thread: RF IQ Quadrature modulator

by ktr
Replies
6
Views
892

### Closed: Re: RF IQ Quadrature modulator

Maybe you can draw the setup in your mind, so we can talk about it?
13. ## Thread: need 7pF to 10pF at 2.5GHz

by ktr
Replies
43
Views
3,349

### Closed: Re: need 7pF to 10pF at 2.5GHz

4-4.5 GHz (500MHz) not wide but not too narrow either.
14. ## Thread: need 7pF to 10pF at 2.5GHz

by ktr
Replies
43
Views
3,349

### Closed: Re: need 7pF to 10pF at 2.5GHz

Reading these makes me sad about my job. How can I find people/material to help me learn about these stuff?

I am currently suffering from a similar phenomeon on extracting the parasitic values of...
15. ## Thread: DDS vs PLL RF Link Budget

by ktr
Replies
1
Views
294

### [SOLVED]Closed: DDS vs PLL RF Link Budget

Hello all,

I am wondering whats the difference between DDS generated chirp and PLL generated chirp's phase noise characteristics in Radar Link budget analysis? It seems many papers reference DDS...
16. ## Thread: Determining Switch Current

by ktr
Replies
8
Views
654

### [SOLVED]Closed: Re: Determining Switch Current

Yeah you are correct, I should not be lazy about these stuff.
However, things get messy in mind from time to time. Thinking about gigahertz level matching and transistors then going back to low...
17. ## Thread: Determining Switch Current

by ktr
Replies
8
Views
654

### [SOLVED]Closed: Re: Determining Switch Current

Hmm, Square wave with aforementioned limits and
I'm not sure with rise time since it will depend on PLL lock time as well.
18. ## Thread: Determining Switch Current

by ktr
Replies
8
Views
654

### [SOLVED]Closed: Re: Determining Switch Current

Hello,

I thought I said it in first post.

100Hz or so is my switch rate, and +3.3 to -1 Volt is my Gate voltage.

Maybe you mean something else?

ktr
19. ## Thread: Determining Switch Current

by ktr
Replies
8
Views
654

### [SOLVED]Closed: Re: Determining Switch Current

Hello,

Although poorly drawn, this is what I mean. I am designing a multi-stage PA, and want to be able to control the current it draws by manipulating gate voltages.

151250

Kind Regards,
...
20. ## Thread: Determining Switch Current

by ktr
Replies
8
Views
654

### [SOLVED]Closed: Determining Switch Current

Hello all,

I have some basic questions regarding capacitor and switch behavior.

Lets say Gate voltage of a transistor is 3.3V and I have bypass capacitors at the gate which makes 5uF in...
21. ## Thread: Via Ground in ADS for connecting source of transistor to ground

by ktr
Replies
5
Views
438

### [SOLVED]Closed: Re: Via Ground in ADS for connecting source of transistor to ground

Ah, I used that transistor before. Nice for high power applications. Although, it have some stability issues, so be careful of that.

You gotta simulate for different via dimaters along the...
22. ## Thread: X-Band Multiple Channel Config

by ktr
Replies
8
Views
773

### [SOLVED]Closed: Re: X-Band Multiple Channel Config

Yes, at first I thought I would put switch after PA, then I realized that switch can not handle 1-2 W power, so I decided to use it before PA, where line power is around 10mW. I will use a secondary...
23. ## Thread: X-Band Multiple Channel Config

by ktr
Replies
8
Views
773

### [SOLVED]Closed: Re: X-Band Multiple Channel Config

I found a switch which I thought good for me. https://www.analog.com/en/products/adrf5027.html this one(SPDT)151134

I am thinking of giving a control voltage with duty cycle proportionate with...
24. ## Thread: How to interpret EMC testing results?

by ktr
Replies
1
Views
992

### Closed: Re: How to interpret EMC testing results?

EMC test is required to determine that your device should have no effect on the other equipment around. Like placing a Transciever in a plane, where there are tens of other equipment around. You need...
25. ## Thread: Vivaldi antenna behave different with and without SMA connector in HFSS

by ktr
Replies
9
Views
786

### Closed: Re: Vivaldi antenna behave different with and without SMA connector in HFSS

whats the definition of "behaving well" and "behaving badly" ?
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