high-speed bandpass filters

[mahdi3999]

Hi everybody,
does anybody know applications where bandpass filters with center frequency as high as 200-300MHz (and maybe even higher) are required? of course RF applications are at much higher frequencies and I'm not looking for those applications.

thanks in advance.

 

[FvM]

I'm not looking for those applications

Means exactly what? You want to disregard all applications related to wireless communication?

 

[barry]

You are asking about applications that use a filter in a certain frequency range, but you don't want to talk about applications in that frequency range? What?

 

[mahdi3999]

I'm looking for any application that uses a bandpass filter in the range of 200-500MHz

 

[Tunelabguy]

Do you have such a filter in hand that you got at a garage sale and now you want to know what to do with it? Or do you want to look at such applications to learn how it it done just out of curiosity?

 

[crutschow]

A 200MHz-500MHz frequency range is normally consider to be RF. LC bandpass filters are common at those frequencies. Any radio operating in that frequency band operates as a tuneable bandpass filter.

 

[Venkadesh_M]

Hi everybody,
does anybody know applications where bandpass filters with center frequency as high as 200-300MHz (and maybe even higher) are required? of course RF applications are at much higher frequencies and I'm not looking for those applications.

thanks in advance.

I think you are doing a project or something and wanted to say the application of the circuit.. This can be used in Higher frequency applications also by means of mixing (converting frequency of carrier in to desired range) you could attain your band pass range....

so it can be used for any particular RF band tuning (like hf vhf) which having your 100MHz band....

 

[mahdi3999]

A 200MHz-500MHz frequency range is normally consider to be RF. LC bandpass filters are common at those frequencies. Any radio operating in that frequency band operates as a tuneable bandpass filter.

hi crutschow,
I forgot to mention that I'm mostly looking for integrated continuous-time applications, as far as I know at these frequecies an integrated inductor has a poor quality factor and also needs a large chip area. On the other hand, structures such as gm-c filters and active-rc filters will be power-hungry in order to circumvent some well-known parasitic effects and in order to have an acceptable amount of gain(required by the type of filter, gm-c or active-rc) . Nevertheless, I have seen some papers that have published low-pass gm-c or active-rc filters with cutoff frequency of around 500MHz. Specifically these filters are used in hard disk drive applications. Have you seen a more specific application or a refrence or a paper using a bandpass filter in the mentioned range? I'm not sure but I think in a radio the mixer converts the input signals frequency to IF(maybe to around a few mega Hz)

 

[FvM]

I forgot to mention that I'm mostly looking for integrated continuous-time applications

I agree this should be mentioned.

Receivers have usually a RF bandpass for preselection puposes (except for some extreme wide-band front ends). But if you look to on-chip radios, they try to avoid an integrated RF filter, for various reasons like noise, dynamic range, power consumption, whatsoever. Means they will refer to a discrete LC or electromechanical resonator at the receiver input.

Analog integrated bandpasses are feasible, but not widely used as far as I'm aware of. I guess you find more considerations in RF IC literature, e.g. Razavi.