How to use $.param with an object inside an array

Question

I have an array that contain several objects and I want to use param to convert the array into a string. Is there a way to do that? Here is the code I have so far.

var spRates = [];

var object =    {
    'name': 'something',
    'rate': {900:30}, // this is what is not working
    'value': 'something'
};

spRates.push(object);

var spRatesString = $.param(spRates, true);

console.dir(spRates);

console.dir(spRatesString); // result: something=something

And this is the array (before using $.param)