How to uncheck Radio button by jquery

Write the Below code to Unchecked Radio Button by Jquery

<script type="text/javascript">
    $(document).ready(function(){
        $("#btn").click(function(){ 
           $('input[name="rd"][type="radio"]:checked').each(function(){ 
               $(this).attr("checked", false); 
            }); 
        });
    });
</script>

<form action="" name="aa" method="post">
    <input type="radio" name="rd" value="1"/>
    <input type="radio" name="rd" value="2"/>
    <input type="radio" name="rd" value="3"/>
    <input type="button" id="btn" value="Click" />
</form>