get the author posts url link of Author Archive Page in WordPress

function fix_canonical() {
    global $paged;
    if (is_category()) {
        $catid = get_query_var('cat');

        echo '
<link rel="canonical" href="'.get_category_link($catid).'" />
<meta name="description" content="'.$meta.'" />';
        if ($paged > 1) echo '
<meta name="robots" content="noindex,follow" />';
    } else {
        echo '';
    }

if (is_tag()) {
        $tagid = get_query_var('tag_id');

        echo '
<link rel="canonical" href="'.get_tag_link($tagid).'" />';
        if ($paged > 1) echo '
<meta name="robots" content="noindex,follow" />';
    } else {
        echo '';
    }
}
add_action('wp_head', 'fix_canonical');

functions.php under my current theme.

As you can see i have got the root permalink for the category and tag archives in the code. Now I want to get the archive link for authors. How can I do it?